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Overgrazing on western rangelands, with special reference to those of British Columbia MacDonald , Malcolm Allan 1949

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OVERGRAZING ON WESTERN RANGELANDS WITH SPECIAL REFERENCE TO THOSE OF BRITISH COLUMBIA A T h e s i s s u b m i t t e d i n P a r t i a l F u l f i l m e n t of the Requirements f o r t h e Degree of MASTER OF SCIENCE IN AGRICULTURE i n the Department of AGRONOMY THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1949• OVERGRAZING ON WESTERN RANGE LANDS WITH SPECIAL REFERENCE TO THOSE OF BRITISH COLUMBIA  ABSTRACT Overgrazing and i t s e f f e c t s has been the s u b j e c t of co n t r o v e r s y and debate i n North America f o r over h a l f a century. I t has been r e f e r r e d to as such and i n connec t i o n with other work i n annual r e p o r t s , e d i t o r i a l s , farmers' b u l l e t i n s , l i v e s t o c k j o u r n a l s , t e c h n i c a l papers and p o l i t i c a l debates. While there are numerous papers d e a l i n g t o t a l l y or i n part with one or more of the aspects of o v e r g r a z i n g , few i f any d e a l with the combined e f f e c t s of o v e r g r a z i n g on the na t i v e v e g e t a t i o n , the domestic l i v e s t o c k , the s o i l , and the w i l d l i f e of the west. A study has been made of i t s e f f e c t s on rangelands of the west with the i n t e n t i o n of encouraging a system of range u t i l i z a t i o n i n B r i t i s h Columbia which w i l l enable the ranchers to d e r i v e the g r e a t e s t p o s s i b l e b e n e f i t s from the i n t e r i o r range lands without s u f f e r i n g the harmful e f f e c t s t h a t overgrazing exerts on the g r a z i n g environment. ACKNOWLEDGEMENT The writer wishes to take this opportunity to thank Dr. V. C. Brink, Associate Professor i n the Department of Agronomy, for his guidance, assistance, and c r i t i c i s m i n the preparation of t h i s study. The writer would also l i k e to thank the members of the Departments of Agronomy and Animal Husbandry for t h e i r i n t e r e s t and suggestions. To the s t a f f s of the Dominion Range Experiment Station, Kamloops, B.C., and the Dominion Experimental Station, Swift Current, Saskatchewan, who so kindly assisted i n obtaining l i t e r a t u r e and information, the writer i s deeply indebted. "God has lent us the earth for our l i f e . It i s a great e n t a i l . It belongs as much to those who are to come after us as to us and we have no right by anything we do or neglect, to involve them i n any un-necessary penalties or to deprive them of the benefit which was i n bur power to bequeath." Ruskin. TABLE OF CONTENTS Page,-ACKNOWLEDGEMENT L INTRODUCTION 1 A. Major Range Regions i n the United S t a t e s ... 2 B. Major Range Regions i n Canada 11 C. Grazing H i s t o r y of the Western Rangelands .. 19 I I . THE EFFECTS OF OVERGRAZING ON NATIVE VEGETATION 28 A. E f f e c t s on Grazing A s s o c i a t i o n s 30 (1) Value of Pla n t I n d i c a t o r s i n Deter-mining Range U t i l i z a t i o n 3'1 (a) I n d i c a t o r s of Range Forage D e t e r i o r a t i o n i n Western North America 33 (b) I n d i c a t o r s of Range Forage D e t e r i o r a t i o n i n I n t e r i o r B r i t i s h Columbia 38 (c) I n d i c a t o r s of Proper Forage U t i l i z a t i o n 43 (2) C l a s s i f i c a t i o n of Ve g e t a t i o n f o r Determining the Degree of Overgrazing 46 (3) The Value of Range Surveys i n Deter-mining Range U t i l i z a t i o n 56 B. E f f e c t s on I n d i v i d u a l P l a n t s 59 I I I . THE EFFECTS OF OVERGRAZING ON DOMESTIC HERBIVORES 62 A. In f l u e n c e on Meat and Wed. Pro d u c t i o n 64 B. Influence on C a l f and Lamb Crops 68 C. In f l u e n c e on Death Losses 69 (1) Poiso nous P l a n t s 69 (2) S t a r v a t i o n and Other F a c t o r s 72 IV. THE EFFECTS OF OVERGRAZING ON THE SOIL 76 A. Water E r o s i o n 78 (1) F a c t o r s I n f l u e n c i n g Water E r o s i o n .... 78 (2) R e s u l t s of Water E r o s i o n 89 B. Wind E r o s i o n 95 (1) F a c t o r s I n f l u e n c i n g Wind E r o s i o n ..... 95 (2) R e s u l t s of Wind E r o s i o n 97 C. Summary of the E f f e c t s of Overgrazing on the S o i l 102 V. OVERGRAZING AND WILDLIFE POPULATIONS ...104 A. Large.Range W i l d l i f e Species 105 B. Small Range W i l d l i f e Spefiies 110 C. Harmful Range Inse c t s 121 D. Predators of W i l d l i f e and Domestic L i v e s t o c k 125 (1) Coyotes 125 (2) Wolves 128 - i i -V. OVERGRAZING AND WILDLIFE POPULATIONS (Cont'd) [3) Other P r e d a t o r s 129 V I . DISCUSSION 2.31 V I I . SUMMARY AND CONCLUSIONS 142 APPENDIX A a _ b APPENDIX B c _ d BIBLIOGRAPHY OVERGRAZING ON WESTERN RANGELANDS' WITH SPECIAL REFERENCE TO THOSE OF BRITISH COLUMBIA I . INTRODUCTION The range a r e a s o f w e s t e r n N o r t h America have been des-c r i b e d by some as a d e s o l a t e d e s e r t e d r e g i o n , g r a z e d t o b a r r e n n e s s , b u f f e t e d by d u s t - s t o r m s , g u t t e d by e r o s i o n g u l l i e s , pocked w i t h gopher h o l e s and b l o w o u t s , s c e n t e d w i t h the pungent odour of sagebrush and strewn w i t h the s k e l e t o n s and remains of g r a z i n g l i v e s t o c k , each a mute symbol of t h e d e s t r u c t i o n brought about by o v e r g r a z i n g . Others c l a i m t h a t t h e r e has been v e r y l i t t l e change i n the v e g e t a t i o n and topography t h r o u g h o u t the y e a r s of g r a z i n g and t h a t t h e r e i s no cause f o r a l a r m . While r a n g e s may be found to s u p p o r t the b e l i e f s and c o n t e n t i o n s of b o t h groups, i t i s w e l l t o study t h e former c o n d i t i o n of r a n g e l a n d s i n o r d e r t h a t the a c t u a l c o n d i t i o n s may be a n a l y z e d . I t i s d i f f i c u l t t o imagine the West as i t i s d e s c r i b e d by the e a r l y "voyageurs" who t o l d o f the tremendous a r e a s o f g r a s s l a n d , r o l l i n g h i l l s , and mountains, p o p u l a t e d o n l y - b y - 2 -wandering bands o f game such as e l k , a n t e l o p e and b u f f a l o and nomadic bands of I n d i a n s such as the Creer; B l a c k f o o t and Navajo. I t i s e s t i m a t e d (230) t h a t b e f o r e s e t t l e m e n t by the w h i t e man the v i r g i n range c o v e r e d the w e s t e r n t w o - t h i r d s of t h e U n i t e d S t a t e s and Canada. E x c l u d i n g such n o n - g r a z a b l e l a n d as mountains, d e s e r t s , dense f o r e s t s and t u n d r a , the range comprised almost 850 m i l l i o n a c r e s i n the U n i t e d S t a t e s a l o n e . N e e d l e s s t o say, w i t h i n t h i s a r e a t h e r e are tremendous v a r i a t i o n s i n v e g e t a t i o n , t o pography, s o i l and c l i m a t e . Re-c o n s t r u c t i o n of the v i r g i n range p i c t u r e w i l l i n d i c a t e t h e range t y p e s t h a t were found by the e a r l y p i o n e e r s . W h i l e most c l a s s i f i c a t i o n s of the v i r g i n range d i f f e r somewhat (214, 242, 230) due t o the i n v e s t i g a t o r ' s i n t e r p r e t a t i o n s o f what c o n s t i t u t e s a major or s e p a r a t e range t y p e , a l l a re b a s i c a l l y s i m i l a r . I n d e s c r i b i n g the v i r g i n range of t h e U n i t e d S t a t e s , the c l a s s i f i c a t i o n s e l e c t e d i s t h a t used by S t o d d a r t and Smith ( 2 1 4 ) . The c l a s s i f i c a t i o n of the g r a z i n g l a n d s o f Canada i s t h a t p r e s e n t e d by C l a r k ( 4 5 , 46, 47) and h i s s t a f f . A. MAJOR RANGE REGIONS OF THE UNITED STATES Nine major g r a z i n g r e g i o n s are r e c o g n i z e d by S t o d d a r t and Smith ( 2 1 4 ) , each w i t h a d i s t i n c t v e g e t a t i o n a l c o m p o s i t i o n . Because of the i n t e r p l a y of s o i l , c l i m a t e , and top o g r a p h y , c l e a r l y d e f i n e d boundary l i n e s between the r e g i o n s a r e i m p o s s i b l e . These r e g i o n s are c l a s s i f i e d as f o l l o w s : ( l ) T a l l G r a s s ; (2) S h o r t G r a s s ; (3) D e s e r t Grass; (4) Bunch Grass or Pa l o u s e G r a s s ; (5) N o r t h e r n o r I n t e r m o u n t a i n Shrub; (6) Southern De s e r t Shrub; (7) C h a p a r r a l ; (8) P i n o n - J u n i p e r ; and (9) C o n i f e r o u s F o r e s t . (1) The T a l l Grass Region T h i s r e g i o n , o f t e n c a l l e d t r u e p r a i r i e , t o t a l l e d some 252 m i l l i o n a c r e s which extended from Manitoba t o Texas a l o n g the M i s s i s s i p p i R i v e r w atershed i n a s t r i p r a n g i n g i n w i d t h from 50 to 500 m i l e s ( 2 1 4 ) . The m o i s t u r e e f f i c i e n c y was h i g h , the a r e a r e c e i v i n g from 25 to 40 i n c h e s o f p r e c i p i -t a t i o n t h r o u g h o u t the g r a z i n g season. The s o i l i s b l a c k and r i c h and the topography smooth and r o l l i n g . The v e g e t a t i o n was abundant and p r o d u c t i v e , b e i n g 2 to 3 f e e t t a l l on the d r i e r s l o p e s and 4 t o 5 f e e t t a l l on t h e bottom l a n d s ( 2 3 0 ) . I n t h i s a r e a , b u f f a l o (204) ranged i n u n c o u n t a b l e h e r d s * and almost every s p e c i e s i n the p l a n t a s s o c i a t i o n was bo t h p a l a t a b l e and n u t r i t i o u s ( 2 3 0 ) . Throughout the t a l l g r a s s r e g i o n the c a r r y i n g c a p a c i t y was h i g h ; o n l y t h r e e - q u a r t e r s t o one and o n e - h a l f a c r e s b e i n g r e q u i r e d t o s u p p l y one a n i m a l month of, g r a z i n g . E a r l y p i o n e e r s found t h a t the v e g e t a t i o n d i d not cure w e l l when l e f t s t a n d i n g and hence l i t t l e l a t e f a l l or w i n t e r g r a z i n g was a v a i l a b l e . (2) The Short Grass Region T h i s a r e a , found to the west of the t a l l g r a s s r e g i o n , i n c l u d e d a p p r o x i m a t e l y 280 m i l l i o n a c r e s (214) i n i t s v i r g i n *E.T. Seton e s t i m a t e d the b u f f a l o p o p u l a t i o n a t 5 0 , 0 0 0 , 0 0 0 head. - 4 -s t a t e . I t extended from t h e Texas Panhandle i n the south to* A l b e r t a and Saskatchewan i n t h e n o r t h , from the f o o t h i l l s of the Rocky Mountains i n the west t o a p p r o x i m a t e l y the 100th m e r i d i a n i n the e a s t where i t merged w i t h the t a l l g r a s s r e g i o n (230). In a l l , . i t formed a b e l t some 300 t o 600 m i l e s wide. The average r a i n f a l l of the a r e a i s much lower t h a n t h a t of the t a l l g rass r e g i o n , b e i n g about 13 i n c h e s i n the n o r t h and somewhat h i g h e r i n the s o u t h e r n p l a i n s . The s o i l was brown and l a c k e d humus, the topography v a s t and u n i f o r m l y l e v e l . The v e g e t a t i o n , as the r e g i o n a l name i n d i c a t e s , was s h o r t , c o n s i s t i n g then as i t l a r g e l y does now o f such hard c u r i n g s p e c i e s as grama, b u f f a l o , wheatgrasses and s p e a r -g r a s s e s . I n t h i s a r e a game b i r d s , r o d e n t s , s m a l l mammals, a n t e l o p e and b u f f a l o (129) u t i l i z e d the f o r a g e t h r o u g h o u t the e n t i r e y e a r . The hot d r y summer winds cured the f o r a g e which m a i n t a i n e d i t s n u t r i t i v e v a l u e t h r o u g h o u t the f a l l and w i n t e r months (42). The g r a z i n g c a p a c i t y of the s h o r t g r a s s r e g i o n was about 2.5 to 4 a c r e s per a n i m a l month i n the n o r t h and i n c r e a s e d t o 5 to 10 a c r e s p e r a n i m a l month i n the s o u t h . There i s some c o n t r o v e r s y among n o t e d e c o l o g i s t s (129, 242) as t o whether t h e s h o r t g r a s s r e g i o n i s a d i s t i n c t r e g i o n o r whether i t i s and was merely a s u b - c l i m a x o f a mixe d - g r a s s a s s o c i a t i o n brought about by the r e p e a t e d heavy g r a z i n g of such a n i m a l s as a n t e l o p e and b u f f a l o . (3) The Des e r t Grass Region T h i s a r e a , synonymously c a l l e d the s e m i - d e s e r t g r a s s r e g i o n (255) o c c u p i e d some 93 m i l l i o n a c r e s and was c o n f i n e d t o t h e s o u t h e r n p o r t i o n s of New Me x i c o , A r i z o n a , and Texas. I t was found t o be much the d r i e s t of the r a n g e l a n d s , h a v i n g low r a i n f a l l (10 to 12 i n c h e s per y e a r ) and e x c e s s i v e l y h i g h e v a p o r a t i o n r a t e s and te m p e r a t u r e s ( 2 1 4 ) . From e a s t t o west the topography changed from b r o a d , f l a t p l a n s and low h i l l s t o mesa t o p s and f i n a l l y to l o w e r s l o p e s of the mountains. The s o i l s are c h a r a c t e r i s t i c a l l y r e d and y e l l o w . The vege-t a t i o n of the r e g i o n was found t o be h i g h l y v a r i a b l e , r a n g i n g from an open g r a s s l a n d t o p a t c h e s of d e s e r t s h r u b s . At the time of p i o n e e r g r a z i n g t h i s a r e a i s r e p u t e d t o have had a c a r r y i n g c a p a c i t y of 20 a c r e s per head per y e a r on a s u s t a i n e d y e a r round g r a z i n g b a s i s . (4) The Bunch Grass Region T h i s r e g i o n o c c u p i e d i n t e r m o u n t a i n a r e a s from A l a s k a and i n t e r i o r B r i t i s h C 0 i u m t > i a through w e s t e r n Montana, southwest-e r n Idaho, e a s t e r n Washington and Oregon t o c e n t r a l C a l i f o r n i a and p o r t i o n s o f Nevada ( 2 4 2 ) . The p r e c i p i t a t i o n o f the bunch g r a s s r e g i o n i s low, r a n g i n g f rom 8 t o 20 i n c h e s per annum. Most of t h i s f a l l s d u r i n g the p e r i o d from e a r l y September t o e a r l y A p r i l ( 2 1 4 ) . The s o i l s under w e l l d e v e l o p e d bunch g r a s s were found t o be b l a c k , h i g h i n l i m e , o r g a n i c m a t t e r and were v e r y p r o -d u c t i v e . Under l e s s w e l l d e v e l o p e d s t a n d s , the s o i l s were s h a l l o w , brown, r o c k y and u n s u i t e d t o c u l t i v a t i o n . The v i r g i n o r c l i m a x v e g e t a t i o n was dominated by bluebunch w h e a t g r a s s , a\ h i g h l y n u t r i t i o u s and e q u a l l y p a l a t a b l e s p e c i e s . Other s p e c i e s e v i d e n t i n the a s s o c i a t i o n were Idaho f e s c u e , g i a n t w i l d r y e , and s p e a r g r a s s e s . Prominent f o r b s were balsam r o o t , mountain d a n d e l i o n and hawksbeard ( 2 3 0 ) . Clements (48) d e s c r i b e d an ar e a i n C a l i f o r n i a , over 100 m i l e s i n e x t e n t , which c o n s i s t e d m a i n l y of n e e d l e g r a s s e s . No q u e s t i o n i s so debated by w e s t e r n e c o l o g i s t s (214) as t h a t of t h e c l i m a x r e l a t i o n s h i p s of the bunchgrass l a n d s t o the s o u t h . I t i s agreed t h a t t r u e g r a s s l a n d i s normal i n the f a r n o r t h e r n a r e a s and on the h i g h e r , m o i s t e r f o o t h i l l s and benches f a r t h e r s o u t h . There i s d i s a g r e e m e n t , however, as to j u s t how much of the g r a s s l a n d has been i n v a d e d by sagebrush owing t o improper g r a z i n g . Many prominent e c o l o - . g i s t s (242) m a i n t a i n t h a t much of so u t h w e s t e r n Idaho and l a r g e a r e a s of e a s t e r n Washington, w e s t e r n Montana, n o r t h e r n Nevada and Utah are c l i m a x g r a s s l a n d . Research and e a r l y r e c o r d s tend to bear out t h i s v i e w p o i n t i n many r e s p e c t s . On the o t h e r hand, the c l i m a t i c s t u d i e s do not l e n d s u p p o r t t o the c o n t e n t i o n t h a t the c l i m a x i s g r a s s l a n d s i n c e g r a s s -l a n d s elsewhere i n the w o r l d r e c e i v e most of t h e r e p r e c i p i t a -t i o n d u r i n g t h e growth p e r i o d ( 1 9 0 ) . C l i m a t i c a l l y , i t would seem t h a t t h i s r e g i o n i s a t r a n s i t i o n between open p a r k l a n d and shrub r e g i o n s . Under c l i m a x c o n d i t i o n s t h i s a r e a c o u l d s u p p o r t one head per a n i m a l month on o n l y 2.2 a c r e s . (5) The I n t e r m o u n t a i n Shrub Region The v i r g i n i n t e r m o u n t a i n shrub r e g i o n l a y between the Rocky Mountains and Cascade Ranges. T h i s r e g i o n , some 96.5 - 7 -m i l l i o n a c r e s i n e x t e n t , was found i n Utah, Nevada, and p a r t s of the a d j a c e n t s t a t e s ( 2 1 4 ) . P r e c i p i t a t i o n over the a r e a i s more abundant i n the dormant season w h i l e the summers are hot and d r y . The annual p r e c i p i t a t i o n i n the r e g i o n i s 6 t o 20 i n c h e s . The v i r g i n s o i l v a r i e d from y e l l o w t o brown, was s h a l l o w and r o c k y , and had l i t t l e or no p r o f i l e development. The topography was rough and i r r e g u l a r . I t i s b e l i e v e d ( 2 4 2 ) t h a t o r i g i n a l l y t h i s r e g i o n was dominated by whea t g r a s s e s w i t h sagebrush and o t h e r brush s p e c i e s o c c u r r i n g o n l y as sub-dominant a s s o c i a t e s or as l o c a l dominants. The U.S. F o r e s t S e r v i c e e s t i m a t e d ( 2 3 0 ) t h a t o n l y 2 . 8 a c r e s were r e q u i r e d p e r animal month on the good sagebrush l a n d s which are today the apparent c l i m a x . (6) The Southern D e s e r t Shrub Region The s o u t h e r n d e s e r t shrub r e g i o n , l o c a t e d i n the v a s t a r i d l a n d s of so u t h e r n C a l i f o r n i a , s o u t h e r n Nevada, s o u t h -w e s t e r n A r i z o n a , s e c t i o n s of s o u t h e r n New Mexico and w e s t e r n Texas, c o n t a i n e d a p p r o x i m a t e l y 51 m i l l i o n a c r e s . However, i n i t s v i r g i n s t a t e o n l y 25 m i l l i o n of the s e a c r e s were found to be g r a z a b l e . T h i s r e g i o n was a l s o found to have the most x e r i c of N o r t h American c l i m a t e s ( 2 1 4 ) . P r e c i p i t a t i o n i s f a r below optimum f o r p l a n t growth, b e i n g o n l y 3 t o 5 i n c h e s a n n u a l l y , and i n extreme c a s e s i t i s known t o t o t a l l e s s t h a n one i n c h f o r a g i v e n y e a r . The p o t e n t i a l e v a p o r a t i o n from a f r e e water s u r f a c e may r e a c h 120 t o 130 i n c h e s per y e a r . I t was noted t h a t the p r e c i p i t a t i o n reaches i t s peak i n the l a t e - 8 -summer a l t h o u g h some s e c t i o n s get l a t e w i n t e r r a i n s . Temper-a t u r e s as h i g h as 130°F. are not uncommon. P i o n e e r t r a v e l l e r s were impressed ( 2 3 0 ) w i t h the b i z a r r e and v a r i e d appearance of t h e p l a n t s on t h e s e s u n s c o r c h e d d e s e r t l a n d s . The U.S. F o r e s t S e r v i c e ( 2 3 0 ) d e s c r i b e d the v e g e t a t i o n as f o l l o w s : " There was l i t t l e u n i f o r m i t y i n the p l a n t c o v e r . Gray s t r e t c h e s of d e s e r t s a l t b r u s h formed dense t h i c k e t s 3 or 4 f e e t t a l l i n v a l l e y s . Over e x t e n s i v e t r a c t s , w i d e l y spaced c r e o s o t e bushes gave the appearance of scrubby o r c h a r d s . On the s u r r o u n d i n g h i l l s and r i d g e s were v a r i e d forms of c a c t i , c e n t u r y p l a n t s , a g a r i s and y u c c a s . Over most of the range p a l a t a b l e f o r a g e was p r o v i d e d by mesquite browse and weeds which sprang up a f t e r r a i n s . The v e g e t a t i o n became more abundant as the h i g h e r e l e v a t i o n s were reached and at the h i g h e s t p o i n t s w i t h i n t h e type were such t r u e f o r a g e s p e c i e s as grama g r a s s e s , s a l t g r a s s and three-awn g r a s s . " I t was c a l c u l a t e d t h a t under v i r g i n c o n d i t i o n s the c a r r y -i n g c a p a c i t y of the s o u t h e r n d e s e r t shrub r e g i o n was about 4 . 5 a c r e s per a n i m a l month ( 2 1 4 ) . (7) The C h a p a r r a l Region Plummer ( 162) has s t a t e d t h a t the word " c h a p a r r a l " i s of Mexican o r i g i n . I t o r i g i n a l l y meant e v e r g r e e n s c r u b oak but has s i n c e come to r e f e r to any s c r u b t y p e . Because of the w i d e l y d i f f e r e n t h a b i t a t c o n d i t i o n s , and the r e s u l t a n t d i f f e r -ences i n the p l a n t a s s o c i a t i o n s , the c h a p a r r a l has a g r e a t l y v a r i e d range use. S t o d d a r t and Smith (214) have d i v i d e d t h i s r e g i o n i n t o t h r e e sub-groups f o r c l a s s i f i c a t i o n and d e s c r i p -t i o n . They l i s t t h ese as f o l l o w s : C a l i f o r n i a c h a p a r r a l , oak s c r u b , and mountain b r u s h . The C a l i f o r n i a c h a p a r r a l o c c u r s over l a r g e a r e a s of - 9 -southern C a l i f o r n i a and s o u t h e r n A r i z o n a . The t o t a l a r e a i s some 5*5 m i l l i o n a c r e s . The d e n s i t y of the c h a p a r r a l i n -c r e a s e s w i t h the e l e v a t i o n e s p e c i a l l y on the n o r t h e r n s l o p e s . The upper l i m i t was found a t about 8000 f e e t where i t g i v e s way to the c o n i f e r o u s f o r e s t . Under v i r g i n c o n d i t i o n s t h i s a r e a was almost e n t i r e l y u n g razed. The oak type a l s o o c c u p i e s l a r g e a r e a s i n the west. As the name i m p l i e s , the p r i n c i p a l v e g e t a t i o n was the many s p e c i e s o f oak which ranged from s c a t t e r e d clumps t o a dense brush s t a n d . The mountain b r u s h type e x i s t s as a narrow t r a n s i t i o n zone between the c o n i f e r o u s f o r e s t and g r a s s l a n d s . I t was noted t o be t y p i c a l l y a so u t h e r n type found p r i n c i p a l l y i n Utah, A r i z o n a , C o l o r a d o and New Mexico (214). T h i s a r e a p o s s e s s e d c o n s i d e r a b l e g r a s s and f o r b growth as an under-s t o r y . The shrubs through t h e i r h i g h n u t r i t i v e v a l u e made t h i s t ype v a l u a b l e f o r g r a z i n g d e s p i t e the draught and rough topography which c h a r a c t e r i z e d the r e g i o n . (8) The P i n o n - J u n i p e r Region T h i s r e g i o n i s c h a r a c t e r i s t i c a l l y s o u t h e r n w i t h o n l y s c a t t e r e d stands o c c u r r i n g n o r t h of t h e 42nd L a t i t u d e . The stan d d i d not occ u r on the west c o a s t , n o r d i d i t cover l a r g e a r e a s e a s t of the Rocky Mountains (230). These low-growing open f o r e s t s of p i n o n s , p i n e s , and j u n i p e r s o c c u r r e d over 74 m i l l i o n a c r e s i n C o l o r a d o , westward t o c e n t r a l Oregon, and south t h r o u g h the f o o t h i l l s c o u n t r y of Utah, Nevada, e a s t e r n C a l i f o r n i a , A r i z o n a , and New Mexico (230). T h i s r e g i o n was - 10 -found at e l e v a t i o n s o f 4000 t o 6000 f e e t . The a r e a i s st e e p and e r o s i o n removes the s o i l r a p i d l y . Low p r e c i p i t a t i o n , u s u a l l y below 16 i n c h e s , and h i g h t e m p e r a t u r e s r e s u l t i n low o r g a n i c m a t t e r p r o d u c t i o n , l e a v i n g an u n p r o d u c t i v e s o i l . The p i n o n - j u n i p e r r e g i o n was an i m p o r t a n t f o r a g e r e s o u r c e . The wide s p a c i n g of" t r e e s p e r m i t t e d the development of c o n s i d e r -a b l e browse such as mountain mahogany, b i t t e r b r u s h and c l i f f -r o s e , a s w e l l as many p a l a t a b l e g r a s s e s and f o r b s . The c a r r y -i n g c a p a c i t y of t h e v i r g i n range was 3 t o 4 a c r e s per cow month. (9) The C o n i f e r o u s F o r e s t Region The c o n i f e r o u s f o r e s t r e g i o n o c c u p y i n g the h i g h e r mois-t u r e r e g i o n s of western Worth America i s c h a r a c t e r i z e d by e v e r g r e e n t r e e s m o s t l y of the genera Pseudotsuga. P j n u s t P i c e a . and Abie s. The p r e c i p i t a t i o n ranges from 15 t o 100 i n c h e s , the a l t i t u d e from sea l e v e l t o 12,000 f t . The s o i l s a r e c h a r a c t e r i s t i c a l l y a c i d . Under v i r g i n c o n d i t i o n s , open stands of s m a l l t r e e s i n the southwest and Rocky Mountain f o o t h i l l s s u p p ort a dense undergrowth of f o r a g e p l a n t s , whereas many of the dense stands and t a l l - g r o w i n g f o r e s t s of the n o r t h w e s t support l i t t l e or no g r a z a b l e undergrowth. Many f o r e s t s ; were found to have l a r g e open p a r k s s u p p o r t i n g e x c e l l e n t s t a n d s o f g r a s s . A l s o of n o t e were the s u b - a l p i n e and a l p i n e meadows. On the ecotone between the f o r e s t s and the g r a s s l a n d s o r sh r u b s , the s o u t h e r n s l o p e s s u p p o r t e d a g r a s s l a n d v e g e t a t i o n , w h i l e the f o r e s t o c c u p i e d t h e m o i s t shaded s l o p e s . Under - 11 -v i r g i n c o n d i t i o n s the g r a z i n g c a p a c i t y of the open f o r e s t t ypes was found t o be a p p r o x i m a t e l y 4 . 0 a c r e s per a n i m a l month ( 2 3 0 ) . B. MAJOR RANGE REGIONS OF CANADA " The v i r g i n range are a s of Canada, l i k e t h e U n i t e d S t a t e s , were found i n the west, namely, M a n i t o b a , Saskatchewan, A l b e r t a and B r i t i s h Columbia. On the Canadian p l a i n s t h e v e g e t a t i o n was m a i n l y g r a s s -l a n d a l t h o u g h shrub and f o r e s t communities were found i n the s a n d h i l l r e g i o n s , - i n the Cypress H i l l s , and i n the Rocky Mountain f o o t h i l l s . Four main r e g i o n s , p r i n c i p a l l y i n g r a s s , are r e c o g n i z e d , namely, t a l l g r a s s , s h o r t g r a s s , mixed g r a s s , and submontane r e g i o n s . The e x t e n t of thes e r e g i o n s i s shown i n F i g u r e 1. L i k e the t a l l and s h o r t g r a s s r e g i o n s of the Canadian p l a i n s , the bunch g r a s s and c o n i f e r o u s f o r e s t r e g i o n s o f B r i t i s h Columbia a re merely the n o r t h e r n e x t e n s i o n s of the r e g i o n s b e a r i n g the same name i n the U n i t e d S t a t e s . (1) The S h o r t Grass Region As p r e v i o u s l y mentioned the s h o r t g r a s s r e g i o n i n Canada i s m e r e l y an e x t e n s i o n of t h a t r e g i o n i n the U n i t e d S t a t e s . However, t h a t r e g i o n i s so v a s t t h a t c o n d i t i o n s found i n the Canadian o r n o r t h e r n e x t r e m i t i e s o f the r e g i o n d i f f e r some-what from th o s e found i n the more so u t h e r n s e c t i o n and a c c o r d -i n g l y t h e Canadian s e c t i o n w a r r a n t s some f u r t h e r e x p l a n a t i o n . - 13 -The Canadian s h o r t g r a s s r e g i o n i s found west of t h e t a l l grass r e g i o n i n an a r e a of low r a i n f a l l . . The average r a i n f a l l , s i m i l a r t o t h a t found i n the n o r t h e r n s h o r t g r a s s r e g i o n of t h e U n i t e d S t a t e s i s a p p r o x i m a t e l y 13 i n c h e s per y e a r (47) but the mean temperature i s somewhat l o w e r and t h e P r e c i p i -t a t i o n - t o - E v a p o r a t i o n R a t i o (P/E R a t i o ) i s h i g h e r . Under v i r g i n c o n d i t i o n s the s o i l i s found t o be brown, l a c k i n g humus arid shows a d i s t i n c t c a l c i u m , l a y e r 15 t o 18 i n c h e s below t h e s u r f a c e ( 4 6 ) , P l a n t growth was g e n e r a l l y s h o r t e r than w i t h i n t h e o t h e r Canadian g r a s s l a n d a s s o c i a t i o n s . Not o n l y were the dominant s p e c i e s n a t u r a l l y low growing,.but t h e y d i d not grow much t a l l e r under more humid c o n d i t i o n s . W h i l e i t was f o u n d t h a t much of the r e g i o n was not s u i t a b l e f o r c e r e a l c r o p s , t h e s e a r e a s were a b l e t o p r o v i d e e x c e l l e n t p a s t u r e s i n c e t h e n a t i v e g r a s s e s c u r e d w e l l and were a l s o p a l a t a b l e and n u t r i t i o u s . I t was f o u n d (46) t h a t under v i r g i n c o n d i t i o n s the c a r r y -i n g c a p a c i t y of t h i s r e g i o n was a p p r o x i m a t e l y 4 a c r e s per cow month. (2) The Mixed Grass Region As F i g u r e 1 i n d i c a t e s , the mixed g r a s s r e g i o n forms a s e m i - c i r c u l a r b e l t around the n o r t h e r n l i m i t s of t h e s h o r t g r a s s r e g i o n . No doubt i t s presence i s due t o s e v e r a l f a c t o r s . Because of the c o o l e r t e m p e r a t u r e s and b e t t e r m o i s t u r e c o n d i -t i o n s ( b o t h c o n t r i b u t i n g to a h i g h e r P/E R a t i o ) t h a n t h o s e found i n the s h o r t g r a s s r e g i o n , t h e r e i s a r i c h e r f l o r a and - 14 -g e n e r a l l y t a l l e r growth p r e s e n t . I t i s d i f f i c u l t t o s e p a r a t e the s h o r t g r a s s r e g i o n from the mixed g r a s s r e g i o n because of the broad t r a n s i t i o n zones where t h e s h o r t g r a s s g i v e s way t o mixed g r a s s a s s o c i a t i o n s and Brown s o i l s g i v e way t o Dark Brown. The f l o r a of the v i r g i n mixed g r a s s r e g i o n was found t o c o n s i s t of both s h o r t and .medium-tall g r a s s e s and from t h i s c h a r a c t e r i s t i c t h e r e g i o n d e r i v e d i t s name. P r a c t i c a l l y a l l the g r a s s e s (46) which o c c u r r e d i n t h e s h o r t g r a s s r e g i o n were a l s o p r e s e n t i n t h e mixed g r a s s r e g i o n a l t h o u g h t h e y o c c u r r e d F i g u r e 2. Mixed g r a s s p r a i r i e and hay meadows i n so u t h w e s t e r n Saskatchewan. The Cypress H i l l s , south of Maple Creek, Saskatchewan, are shown i n the background. - 15 -i n d i f f e r e n t p r o p o r t i o n s . However, s e v e r a l s p e c i e s were found which were not p r e s e n t i n the s h o r t g r a s s r e g i o n , namely such dominants as short-awned p o r c u p i n e g r a s s , n o r t h e r n w h e a t g r a s s , rough f e s c u e and green n e e d l e g r a s s . I t was found t h a t under v i r g i n c o n d i t i o n s the c a r r y i n g c a p a c i t y of t h i s r e g i o n was a p p r o x i m a t e l y 2.5 a c r e s per cow month ( 4 6 ) . (3) The Submontane Region T h i s r e g i o n occurs a d j a c e n t t o the mixed g r a s s r e g i o n a t h i g h e r l a t i t u d e s and a l t i t u d e s i n t h e Cypress H i l l s , Rocky Mountain f o o t h i l l s and n o r t h e r n p r a i r i e s ( 4 7 ) . I t i s a l s o a s s o c i a t e d w i t h c o o l e r t e m p e r a t u r e s and s l i g h t l y m o i s t e r c o n d i t i o n s t h a n those under which the mixed g r a s s r e g i o n i s d e v e l o p e d . A l t h o u g h the r e g i o n i s found f o r the most p a r t on the B l a c k S o i l Zone, i t may a l s o develop on t h e S h a l l o w B l a c k and i n some cases the Dark Brown S o i l Zone. Under v i r g i n range c o n d i t i o n s , rough f e s c u e was t h e dominant g r a s s s p e c i e s , w h i l e o t h e r i m p o r t a n t s p e c i e s were June g r a s s , awned wheat-g r a s s , Idaho f e s c u e and oat g r a s s . Forbs were r e l a t i v e l y abundant and aspen, r o s e s and w i l l o w s were p a r t i c u l a r l y p r e -v a l e n t a l o n g c o u l e e s and n o r t h e r n s l o p e s . P i n e t r e e s were found i n t h e ecotone between the g r a s s l a n d s and f o r e s t . Under v i r g i n c o n d i t i o n s , t h e c a r r y i n g c a p a c i t y of t h i s r e g i o n v a r i e d from 1.25 t o 2 a c r e s per cow month. (4) The Bunch Grass Region As p r e v i o u s l y mentioned, t h i s r e g i o n was found i n t h e i n t e r m o u n t a i r i a r e a s of i n t e r i o r B r i t i s h Columbia where i t was - 16 -c o n f i n e d t o the v a l l e y bottoms and a d j a c e n t s l o p e s . The g r a s s l a n d a r e a , t o t a l l i n g some 3 t o 4 m i l l i o n a c r e s (227) i s an e x t e n s i o n of t h e bunch g r a s s r e g i o n of the U n i t e d S t a t e s ( 2 4 2 ) . The p r e c i p i t a t i o n i s low, v a r y i n g from 8 t o 20 i n c h e s . Three main s u b d i v i s i o n s or communities s i m i l a r t o those d e s c r i b e d by Daubenmire (64) i n Washington a r e e v i d e n t ( 2 0 6 ) . On account of t h e i r v e r t i c a l d i s t r i b u t i o n , t h e s e p l a n t communities were d e s i g n a t e d as the Lower, M i d d l e and Upper G r a s s l a n d zones. The Lower G r a s s l a n d b e l t o c c u r r e d a t e l e v a t i o n s of 1100 t o about 2300 f e e t and c o i n c i d e d w i t h t h e Brown E a r t h zone. From 2300 t o 2800 f e e t was found the M i d d l e G r a s s l a n d zone, a s s o c i a t e d w i t h Dark Brown s o i l s . The Upper G r a s s l a n d zone extended from the upper edge of t h e M i d d l e G r a s s l a n d s t o t h e f o r e s t edge a t about 3200 f e e t and c o i n c i d e d w i t h t h e B l a c k E a r t h zone. A l l t h r e e g r a s s l a n d communities were dominated under v i r g i n c o n d i t i o n s by p e r e n n i a l bunch g r a s s e s , t h e b a s i s f o r the a r e a ' s c l a s s i f i c a t i o n . Under v i r g i n or c l i m a x c o n d i t i o n s , the c a r r y i n g c a p a c i t y of t h i s a r e a was s i m i l a r t o t h a t of t h e bunch g r a s s r e g i o n i n the n o r t h w e s t e r n U n i t e d S t a t e s . (5) The C o n i f e r o u s F o r e s t Region I n B r i t i s h Columbia and A l b e r t a t h e c o n i f e r o u s f o r e s t r e g i o n o c c u p i e d t h e h i g h e r m o i s t e r r e g i o n s . As p r e v i o u s l y mentioned, the dense s t a n d s and t a l l - g r o w i n g f o r e s t s s u p p o r t e d l i t t l e or no g r a z a b l e undergrowth. T h i s was - 18 -p a r t i c u l a r l y t r u e i n areas of high r a i n f a l l . In B r i t i s h Columbia the c o n i f e r o u s f o r e s t r e g i o n was the l a s t to be claimed f o r summer g r a z i n g . I t i s estimated that there are about 10 m i l l i o n acres of c o n i f e r o u s f o r e s t capable of supporting t h i s type of g r a z i n g (227). As was the case w i t h the B.C. g r a s s l a n d s , t h i s r e g i o n was d i v i d e d i n t o three com-muni t i e s . They are the Montane, Subalpine and Upper Sub-a l p i n e f o r e s t s (64) and c o i n c i d e with the Lower, Middle and Upper Podsols r e s p e c t i v e l y . Shrubs f l o u r i s h i n the Montane zone where the t r e e coyer i s f a i r l y open. Grasses and other herbs grow'well i n both the Montane and Upper Subalpine communities, but are l e s s v i g o r o u s and common i n the Sub-a l p i n e zone. The Upper Subalpine i s c h a r a c t e r i z e d by d i f f e r ences i n t r e e d e n s i t y and growth as w e l l as by the presence extensive t r e e l e s s meadows which produce l a r g e amounts of grasses and sedges. Since the coniferous f o r e s t r e g i o n was the l a s t t o be u t i l i z e d f o r g r a z i n g and s i n c e i t i s capable of s u p p o r t i n g summer g r a z i n g only, f a r l e s s g r a z i n g harm has been done i n t h i s r e g i o n than elsewhere. Under v i r g i n c o n d i t i o n s , the grazing c a p a c i t y of the open c o n i f e r o u s f o r e s t r e g i o n was found t o equal that of the areas c l a s s i f i e d s i m i l a r l y i n the northwestern United S t a t e s . - 19 -F i g u r e 4. L i v e s t o c k g r a z i n g a n a t i v e meadow i n the Montane F o r e s t near Pass Lake, B.C. C. GRAZING HISTORY OF THE WESTERN RANGELANDS Befor e t h e p r e s e n t range c o n d i t i o n i s d i s c u s s e d , i t i s w e l l t o t r a c e , i n b r i e f , t h e h i s t o r y of l i v e s t o c k g r a z i n g over the rangelands of w e s t e r n N o r t h America. H i s t o r y ' s f i r s t mention of the i n t r o d u c t i o n of domestic g r a z i n g a n i m a l s t o western North America was i n 1521 when V i l l a l a b o s i n t r o -duced A n d a l u s i a n c a t t l e t o Mexico. I n 1540 Coronado l e d the " C o n q u i s t a d o r e s " from Mexico onto t h e p l a i n s o f l u s h g r a s s t h a t i s now Texas (230).- W i t h h i s e x p e d i t i o n were bands o f h o r s e s , c a t t l e and sheep. I t i s b e l i e v e d t h a t t h e sheep - 20 -p e r i s h e d but c a t t l e and h o r s e s s u r v i v e d and t o some degree were a g a i n d o m e s t i c a t e d by the I n d i a n s , By 1800 t h e s e " w i l d " h o rses.and " w i l d " c a t t l e , and I n d i a n l i v e s t o c k i n g e n e r a l were w e l l developed as f a r n o r t h as B r i t i s h Columbia ( 8 7 ) . By t h i s t i m e t h e S p a n i s h Mexicans had d e v e l o p e d t h e p r a c t i c e s of b r a n d i n g , r o p i n g , the s t o c k s a d d l e , and many o t h e r f e a t u r e s which are s t i l l prominent i n our p r e s e n t day methods of range l i v e s t o c k management. By 1800, b e f o r e the s e t t l e r s from t h e U n i t e d S t a t e s had • c r o s s e d the A l l e g h a n i e s , t h e S p a n i s h and Mexicans had e s t a -b l i s h e d from San Diego n o r t h on t h e west c o a s t . ( I n w e s t e r n Canada d u r i n g t h e same p e r i o d of time the Hudson's Bay Com-pany p a i d l i t t l e a t t e n t i o n t o the v a s t g r a z i n g a r e a s o f A l b e r t a and Saskatchewan s i n c e b u f f a l o h i d e s and w o l f s k i n s , the p r i n c i p a l commodities of the p l a i n s , were not h i g h l y p r i z e d by the Company.) In 1821 the Mexican government i n v i t e d Americans t o s e t t l e i n Texas and by 1830 t h e g r e a t " h i d e and t a l l o w " empire of Borden was w e l l e s t a b l i s h e d . S i n c e the a r e a of p r o d u c t i o n was so f a r removed from t h e c e n t e r s of p o p u l a t i o n , t h e s e were t h e o n l y commodities t h a t c o u l d be marketed. I n 1834, Dana i n h i s Two Years B e f o r e t h e Mast n o t e d t h a t a s i n g l e t r a d i n g v e s s e l p i c k e d up 40,000 h i d e s a t t h r e e C a l i -f o r n i a p o r t s , San Diego, Monterey and Santa B a r b a r a d u r i n g one t r i p . By 1840, t h e Hudson's B a y Company had e s t a b l i s h e d herds of h o r s e s and c a t t l e a t i t s post a t Kamloops, B.C. The y e a r - 21 -1850 witnessed the t r a i l i n g of the f i r s t great herds of Texas longhorns to Ohio. The p r a c t i c e of t r a i l i n g i n c r e a s e d throughout the west u n t i l 1885. In 1858 gold was d i s c o v e r e d i n c e n t r a l B r i t i s h Columbia; soon afterwards c a t t l e were being t r a i l e d even to t h i s then-remote part of the Northwest. From January, 1861, to December, 1862, f o r example, 4,817 c a t t l e , 3,396 horses, 770 mules, and 1,310 sheep were recorded at the Canadian Customs, Osoyoos, B.C. during t h e i r northward t r e k (234). Among noted pioneers who drove c a t t l e to B.C. about t h i s time were Jerome Harper, who e s t a b l i s h e d the Harper Ranch north of Kamloops i n 1862, and his b r o t h e r , who e s t a -b l i s h e d the famous Gang Ranch i n 1863. The year 1863 a l s o witnessed the establishment of the ranching i n d u s t r y at the m i l e houses along the Cariboo Road. By 1872, ranching was w e l l developed i n the N i c o l a , Okanagan, and Kamloops areas and B r i t i s h Columbia was producing one h a l f i t s beef requirements. The decade 1870 to 1880 brought many more changes i n B.C. ranching amongst which were such noteworthy events as the establishment of communication throughout the Okanagan i n the form of a wagon road. C a t t l e , too, were f i r s t t r a i l e d from the Similkameen V a l l e y to Hope and the coast markets. About the same time (1871, 1872) i n A l b e r t a , the McDougall brothers brought 150 head of horses and c a t t l e t o Morley-v i l l e west of Calgary. T h i s decade of the '70's a l s o w i t -nessed the establishment of the West's f i r s t Stockmen's A s s o c i a t i o n . - 22 -I t has o f t e n been s a i d t h a t the next decade (1880-1890) was the most e v e n t f u l i n w e s t e r n r a n c h i n g h i s t o r y , b oth i n the U n i t e d S t a t e s and i n Canada. I n t h e U n i t e d S t a t e s , 1883 marked the r i s e of c a t t l e r a n c h i n g as " b i g b u s i n e s s " . I n Wyoming a l o n e , 20 l a r g e c a t t l e companies were formed w i t h a t o t a l c a p i t a l i z a t i o n of over $12,000,000 ( 1 5 0 ) . Of t h e s e , the Union C a t t l e Company was i n c o r p o r a t e d f o r $2,000,000; t h e N o r t h American C a t t l e Company and the S e a r i g h t C a t t l e Company f o r $1,000,000 each. Wyoming was m e r e l y a r e p r e -s e n t a t i v e a r e a ; the same t h i n g was happening or had happened up and down the Great P l a i n s from Montana t o Texas. The XIT o u t f i t i n t h e Texas Panhandle r a n about 150,000 head on 3,000,000 ac r e s of l a n d — 25 m i l e s e a s t and west by 200 m i l e s n o r t h and so u t h (24). O u t f i t s of 5,000 t o 10,000 head were common on the p l a i n s and i n t h e Southwest, and p r o p e r t i e s of s m a l l owners were o f t e n c o n s o l i d a t e d by purchase or by i n -c o r p o r a t i o n . In western Canada t o o , r a n c h i n g became " b i g b u s i n e s s " , v i z . , t h e f o r m a t i o n of the Douglas Lake C a t t l e Company (1886) and the Gang Ranch (1880) i n B r i t i s h Columbia; t h e Bar U f i n a n c e d by A l i e n s o f M o n t r e a l , t h e Waldron and Oxley Ranches by B r i t i s h c a p i t a l and the Cochrane Ranch, i n A l b e r t a . By 1884 f o r t y - o n e companies and i n d i v i d u a l s h e l d u n f e n ced l e a s e s on t h e s h o r t g r a s s p r a i r i e s of Canada w i t h l e a s e s t o t a l l i n g almost 3 m i l l i o n a c r e s over w h i c h 47,000 head 'of c a t t l e g r a z e d . The s e t t l e m e n t of I n d i a n s on r e s e r v a t i o n s d u r i n g t h e 19th C e n t u r y i s a f a c t o r t h a t d i d much toward- p e r m i t t i n g t h e - 23 -establishment of ranching in the West. As long as the Indians l a i d claim to grazing lands, the ranching industry-was impaired or prevented, depending on the disposition of the tribes occupying those regions. There are many accounts in the l i t e r a t u r e of s t r i f e and bloodshed stemming from this very claim. The Canadian P a c i f i c Railway reached the p r a i r i e s i n 1883 thereby providing a means of access to the r i c h eastern markets and transportation west f o r the farmsteaders and s e t t l e r s . In 1885 the R i e l Rebellion troops proved a market for beef and in 1887 the f i r s t shipment of beef to the United Kingdom v i a the C.P.R. was completed. By 1885 a t o t a l of more than 5 m i l l i o n head of c a t t l e had been driven northward from Texas (150) mainly to r a i l centers for shipment East. Other important changes were i n the making at t h i s time. The c a l f crop had risen to 25 percent, purebred c a t t l e were introduced to the West, v i z . , the importations of purebred Herefords, Shorthorns and Devons by the Utah Mormons, Short-horns by the Oxley Ranch (Alberta) and pedigree b u l l s by the Cochrane Ranch (Alberta). Also of revolutionary impor-tance was the change i n ranch management and the decline of the "Spanish" influence. Prior to the severe winters of 1882-83 and 1886-67, no winter feed had been prepared; with the heavy losses experienced during these winters i t became evident that hay production was necessary to offset these losses i n the future. Some conservationists have claimed that t h i s was one of the f i r s t steps toward overgrazing. - 24 -The decade 1880 to 1890 saw the r i s e of the western sheep industry, widespread farm settlement throughout much of the west, of i r r i g a t i o n , and of the i n i t i a t i o n of government' grazing controls. The addition of large numbers of sheep and farming settlement to areas already carrying maximum numbers of cattle precipitated many violent disagreements regarding the use of rangeland. In C a l i f o r n i a , the gold boom resulted i n an increase i n sheep numbers from one m i l l i o n i n 1859 to 6.9 m i l l i o n i n 1880, while i n 1882 there were 5.2 mi l l i o n i n New Mexico and 5.7 m i l l i o n i n Texas (280). These vast numbers of sheep, appearing almost without warning on the f u l l y used c a t t l e ranges not only aroused deep resentment among the cattlemen but had a dire effect i n causing even further exhaustion of the range forage. In some instances, since c a t t l e fences did not stop the sheep, hay f i e l d s were invaded and the.crop destroyed. Settlement which competed with both the c a t t l e and sheep industries further i n t e n s i f i e d the already severe range use. In many areas, e s p e c i a l l y mountain and f o o t h i l l s l o c a l i t i e s , settlement claimed much of the spring and f a l l range which was, even at that time, i n short supply. For many years, ranchers had no protection since s e t t l e r s were given p r i o r i t y i n land usage. However, not a l l the influences of settlement and cu l t i v a t i o n were harmful to the range. I r r i g a t i o n to increase forage production complemented the grazing lands providing feed f o r stock during periods of short supply. Since barbed wire had become common, the great c a t t l e d r i v e s from the southwest t o the eastern S t a t e s had ceased or swung north to the Canadian P l a i n s . In B r i t i s h Columbia the K e t t l e V a l l e y l i n e (completed i n 1897) c r e a t e d i n i t s c o n s t r u c t i o n a ready market and once again the grazing i n -dustry i n B r i t i s h Columbia was rej u v e n a t e d . At the t u r n of the Century i n v e s t i g a t o r s began to p u b l i s h warnings (92, 93, 18, 168, 91) of- the harm t h a t the " g e t - r i c h - q u i c k ^ methods of g r a z i n g were doing to the ranges. In the United States the r e p o r t s v a r i e d from i n t e r v i e w s . w i t h " o l d - t i m e r s " i n the grazing d i s t r i c t s t o d e t a i l e d s t a t i s t i c a l r e p o r t s . At t h i s time i t was g e n e r a l l y agreed t h a t range d e t e r i o r a t i o n was t r a c e a b l e to two mistaken i d e a s ; f i r s t l y , t h a t the range can c a r r y the maximum number of stock without d e t e r i o r a t i o n year a f t e r year and, secondly, that i n order to get the most out of a range i t must be stocked to i t s maximum c a r r y i n g c a p a c i t y . These i d e a s , needless t o say, were put i n t o p r a c t i c e and g r a d u a l l y v a s t areas of " u n l i m i t e d " g r a z i n g lands were reduced, not only by c u l t i v a t i o n , i r r i g a t i o n , e r o s i o n , and f e n c i n g , but a l s o by ov e r g r a z i n g . . I t i s now a matter of h i s t o r y ( F i g u r e 5) that i n every range r e g i o n , o v e r g r a z i n g has r e s u l t e d i n a r e d u c t i o n i n c a r r y i n g c^a-pal-city (230). Needless t o say, the r e d u c t i o n i s not u n i v e r s a l i n a l l areas throughout each r e g i o n , but i t i s upon the average forage p r o d u c t i o n per acre and the t o t a l p a l a t a b l e forage p r o d u c t i o n per area t h a t l i v e -stock u n i t s are produced. The f a c t t h a t o v e r g r a z i n g i s present to such a marked CD c r CD o r • p C J . O CD *i T 3 Q CD 1 c+-P H * N O H- 3 a H* fcl CD c+ oq c r H* CD O B o CO p • <i H-OP o p T 3 P o T H E REDUCTION IN CARRYING CAPACITY OF THE M A J O R GRAZING REGIONS-TALL GRASS SHORT GRASS DESERT GRASS BUNCH GRASS INTER-MOUNTAIN SHRUB SOUTHERN D. SHRUB CHAPARRAL PINON-JUNIPER OPEN C. FOREST ACRES REQUIRED PER COW MONTH VIRGIN PRESENT Tzm V/////A '///////////A ////////////////A V///////A 0 3 6 12 15 18 - 27 -degree i n t r o d u c e s many complex problems i n range management and l i v e s t o c k p r o d u c t i o n . I s the r e d u c t i o n i n p a l a t a b l e f o r -age p r o d u c t i o n the o n l y problem? Does o v e r g r a z i n g upset t h e e c o l o g i c a l b a l a n c e ? May t h i s upset m a n i f e s t i t s e l f i n such a r e a s , i n the form of f l o o d s , dust storms, e r o s i o n and i n c r e a s e s i n h a r m f u l i n s e c t p o p u l a t i o n s , r o d e n t s and p r e -d a t o r y a n i m a l s ? Does o v e r g r a z i n g r e s u l t i n a r e d u c t i o n i n d e s i r e d w i l d l i f e numbers? Does i t cause i n c r e a s e s i n m e c h a n i c a l l y i n j u r i o u s and poisonous p l a n t p o p u l a t i o n s ? The l i t e r a t u r e c o v e r i n g the s u b j e c t i s e x t e n s i v e and a b s o r b i n g . I t i s t h e purpose o f t h i s T h e s i s t o c o l l e c t , d i s -seminate and c r i t i c a l l y d i s c u s s some o f the c o n t r o v e r s i a l problems of o v e r g r a z i n g w i t h a v i e w t o a p p l y i n g the i n f o r m a -t i o n g a i n e d t o t h e problems of o v e r g r a z i n g p r e s e n t t hroughout the range are a s of B r i t i s h Columbia. - 28 -I I . THE EFFECTS OF OVERGRAZING ON NATIVE VEGETATION To the p l a n t e c o l o g i s t , t h e range manager, and the con-s e r v a t i o n i s t , t h e terms used t o d e s c r i b e g r a z i n g r e g i o n s and v e g e t a t i o h a l c o n d i t i o n s p r e s e n t no problem s i n c e t h e y con-s t i t u t e a component p a r t of t h e i r t e c h n i c a l v o c a b u l a r y . To the layman, however, t h i s t e r m i n o l o g y s e r v e s o n l y t o c o n f u s e . The numerous c o m b i n a t i o n s of f a c t o r s a f f e c t i n g r a n g e l a i i d v e g e t a t i o n have r e s u l t e d i n c o r r e s p o n d i n g l y numerous d e s c r i p -t i v e t e rms. However, the g e n e r a l use of t h e s e terms has r e n d e r e d u s e l e s s many ex a c t d e f i n i t i o n s . Others have become so r e s t r i c t e d i n t h e i r a p p l i c a t i o n t h a t i t i s d i f f i c u l t t o employ them. S e v e r a l c l a s s i f i c a t i o n s of t h e n a t i v e v e g e t a t i o n have been made by e c o l o g i s t s t h a t i n p a r t are a p p l i c a b l e t o range usage. In s p i t e of t h i s i t i s g e n e r a l l y d e s i r a b l e t o d e v i a t e from t h e s e c l a s s i f i c a t i o n s and d e l i m i t v e g e t a t i o n l a r g e l y a c c o r d i n g t o g r a z i n g v a l u e . An example of such a c l a s s i f i c a t i o n has been p r e s e n t e d i n t h e I n t r o d u c t i o n . The terms g r a z i n g type and v e g e t a t i o n t y p e a r e not d i s t i n c t i n t h e i r usage and may r e f e r t o v a r i o u s k i n d s of s p e c i e s or t o v a r i o u s v e g e t a t i o n d e n s i t i e s of a p p r o x i m a t e l y the same s p e c i e s c o m b i n a t i o n , o f t e n r e f e r r e d t o as s u b - t y p e s . Many v e g e t a t i o n t y p e s a r e r e c o g n i z e d by t e c h n i c a l range managers. These ty p e s have no e c o l o g i c a l b a s i s but a r e - 29 -d e t e r m i n e d , r a t h e r , by t h e d o m i n a t i n g s p e c i e s or what appears t o be d o m i n a t i n g . The term v e g e t a t i o n r e g i o n i s suggested t o a p p l y to broad c l a s s e s of v e g e t a t i o n i n c l u d i n g a r e a s dominated by s e v e r a l s p e c i e s . P l a n t e c o l o g i s t s g e n e r a l l y agree t h a t not o n l y i s the v e g e t a t i o n c o n s t a n t l y u n d e r g o i n g v a r i o u s k i n d s of change but a l s o t h a t the i n c r e a s i n g h a b i t of c o n c e n t r a t i n g a t t e n t i o n on t h e s e changes i n s t e a d of s t u d y i n g p l a n t communities as i f t h e y were s t a t i c e n t i t i e s l e a d s to a f a r g r e a t e r u n d e r s t a n d i n g of th^e n a t u r e of v e g e t a t i o n and the p a r t i t p l a y s i n t h e w o r l d . A g r e a t p a r t of v e g e t a t i o n a l change i s g e n e r a l l y known as s u c c e s s i o n which has become a r e c o g n i z e d t e c h n i c a l term i n e c o l o g y ( 2 2 0 ) . A s u c c e s s i o n i s a c o n t i n u o u s p r o c e s s of change i n vege- k t a t i o n w h i c h can be s e p a r a t e d i n t o a s e r i e s of phases. G e n e r a l l y s p e a k i n g , however, i t i s the p r o c e s s whereby one s p e c i e s or a s s o c i a t i o n of s p e c i e s r e p l a c e s a n o t h e r . Among the n a t u r a l causes of s u c c e s s i o n a l change are changes i n s o i l and c l i m a t i c f l u c t u a t i o n s . Induced s u c c e s s i o n , i . e . , t h a t r e s u l t i n g f r om some b i o l o g i c a l d i s t u r b a n c e such as g r a z i n g or i n s e c t i n v a s i o n , l e a d s away from the normal or c l i m a x c o n d i t i o n . A c l i m a x i s a r e l a t i v e l y s t a b l e s t a t e r e a c h e d by suc-c e s s i o n a l change. Change may s t i l l be p r o c e e d i n g w i t h i n a c l i m a x , but i f i t i s t o o s l o w t o be a p p r e c i a t e d or too s m a l l t o a f f e c t the g e n e r a l n a t u r e o f t h e ' v e g e t a t i o n , the a p p a r e n t l y s t a b l e phase must be c a l l e d a c l i m a x . The h i g h e s t t y p e s of - 30 -v e g e t a t i o n c h a r a c t e r i s t i c of a c l i m a t i c r e g i o n and l i m i t e d o n l y by c l i m a t e form the c l i m a t i c c l i m a x . Other c l i m a x e s may be d e v e l o p e d by o t h e r f a c t o r s such as s o i l t y p e s , g r a z i n g a n i m a l s , f i r e , e t c . (220). An i n s p e c t i o n of p l a n t s o c i e t i e s shows t h a t t h e y a r e f a r from u n i f o r m . In many cases p r i n c i p a l or s e c o n d a r y s p e c i e s may form minor groups c a l l e d c o mmunities. Communities are e a s i l y r e c o g n i z e d i n the case of s p e c i e s where i n d i v i d u a l s grow i n groups. Many o t h e r terms such as a s s o c i a t i o n , ecotone. dominant. e t c . , a r e commonly used throughout t h e l i t e r a t u r e , each s e r v i n g t o r e n d e r e c o l o g i c a l d i s c u s s i o n s more e x a c t i n g . The t r u e v a l u e of t h e s e terms and t h e i r meaning, however, can o n l y be m a i n t a i n e d by a s t r i c t and p r o p e r usage. The o r i g i n and usage of such terms i s both i n t e r e s t i n g and a b s o r b i n g . U n f o r t u n a t e l y , i t i s not p o s s i b l e to e n l a r g e f u r t h e r at t h i s p o i n t . A. EFFECTS ON GRAZING ASSOCIATIONS In o r d e r t h a t p l a n t s i n an a s s o c i a t i o n may grow, t h e y must absorb water and e s s e n t i a l p l a n t - f o o d elements from the s o i l and t r a n s f e r them to t h e l e a v e s where p h o t o s y n t h e s i s manufactures the m a t e r i a l s which make p o s s i b l e f u r t h e r growth, the development of seeds, and, of prime importance i n range f o r a g e management, the s t o r a g e of food f o r w i n t e r maintenance and the b e g i n n i n g o f herbage growth t h e f o l l o w i n g s p r i n g . I f the p h o t o s y n t h e t i c p a r t s are removed by g r a z i n g b e f o r e nutrients - 31 -have been s y n t h e s i z e d t o t a k e c a r e of the e s s e n t i a l growth f u n c t i o n s , t h e p l a n t s ' v i g o r w i l l be sapped. I f the n u t r i e n t s u p p l y i s i n a d e q u a t e , the p l a n t may d i e . I t i s t h e r e f o r e v i t a l l y i m p o r t a n t t o have a s u b s t a n t i a l l e a f a g e a v a i l a b l e on p l a n t s t h r o u g h o u t the growing season. In the range areas of the west t h e r e i s a somewhat c r i -t i c a l b a l a n c e between the m o i s t u r e a v a i l a b l e f o r p l a n t growth and the needs of the p l a n t c o v e r , w i t h a r e s u l t i n g c o m p e t i t i o n f o r m o i s t u r e . When g r a z i n g i s i n t r o d u c e d and t h e range i s o v e r s t o c k e d , t h e p a l a t a b l e p l a n t s a r e g r a z e d f i r s t and s e v e r e -l y and hence t h e y s u f f e r most i n t h i s i n t e n s e c o m p e t i t i o n . The i n e v i t a b l e r e d u c t i o n i n b a s a l a r e a of the p a l a t a b l e p l a n t s reduces t h e c o m p e t i t i o n f o r the sub-dominants g i v i n g them a chance t o i n c r e a s e i n d e n s i t y . When o v e r g r a z i n g i s c o n t i n u e d u n p a l a t a b l e s p e c i e s become dominant. O v e r g r a z i n g f o r a p r o l o n g e d p e r i o d of t i m e i s i n d i c a t e d by the v e g e t a t i o n p r e s e n t (120), e s p e c i a l l y by the s c a r c i t y of th e p r e f e r r e d range p l a n t s and the p r e v a l e n c e of a n n u a l weeds and g r a s s e s . S i g n s which a r e a l s o e v i d e n t a r e the presence of dead and p a r t l y dead stumps of s h r u b s , damage t o t r e e r e p r o d u c t i o n , and e r o s i o n and b a r r e n n e s s of t h e s o i l , u s u a l l y marked w i t h s t o c k t r a i l s . These p l a n t i n d i c a t o r s a re i n v a l u -a b l e i n d e t e r m i n i n g t h e e f f e c t s 'of o v e r g r a z i n g on the n a t i v e v e g e t a t i o n . ( l ) The Value of P l a n t I n d i c a t o r s i n D e t e r m i n i n g Range U t i l i z a t i o n  Sampson (175) s t a t e s t h a t the p l a n t i n d i c a t o r concept i s - 3 2 -based on a c a u s e - e f f e c t r e l a t i o n s h i p , where the e f f e c t i s t a k e n as a s i g n of the cause. A l l p l a n t s are a measure or i n d i c a t o r of t h e i r environment. Because growth and p l a n t p r o -d u c t i o n are governed by the h a b i t a t , any p l a n t s p e c i e s may se r v e as an i n d i c a t o r of the c o n d i t i o n s of i t s h a b i t a t . How-ev e r , o n l y a few s p e c i e s are s e l e c t i v e enough to be c o n s i d e r e d as good i n d i c a t o r s . Clements (49) s t a t e s : " The problem of i n d i c a t o r v a l u e s i s c h i e f l y one of a n a l y z i n g the f a c t o r complex, t h e h a b i t a t , and of r e l a t i n g the f u n c t i o n a l and s t r u c t u r a l r esponse of both p l a n t and community to i t . " Nee d l e s s to say, a p l a n t s p e c i e s t h a t i s found i n a v a r i e t y of c i r c u m s t a n c e s i s f a r l e s s r e l i a b l e as an i n d i c a t o r o f range c o n d i t i o n s than one r e q u i r i n g more e x a c t i n g growth c o n d i t i o n s . Dominants which do not e n j o y an e s p e c i a l l y wide range are c o n s i d e r e d b e t t e r i n d i c a t o r s u s u a l l y because t h e y r e a c t more v i o l e n t l y t o the changes i n h a b i t a t . S i m i l a r l y , a group of p l a n t s or an a s s o c i a t i o n i s r e g a r d e d as a b e t t e r i n d e x o f range g r a z i n g c o n d i t i o n s t h a n one s p e c i e s . The v e g e t a t i o n w i l l i n d i c a t e a c o n d i t i o n of o v e r g r a z i n g , however, o n l y when t h e f o r a g e p r e s e n t has been c o r r e l a t e d w i t h the s o i l s t r u c t u r e , t r a n s f o r m a t i o n of a s p e c t , and w i t h a r e l i a b l e h i s t o r y of economic u t i l i z a t i o n (175). Clements (49) c o n s i d e r s the dominant s p e c i e s which com-p r i s e a c l i m a x a s s o c i a t i o n t o be the most r e l i a b l e i n d i c a t o r s . He urges the use of keen judgment i n s e l e c t i n g p l a n t i n d i c a -t o r s . S u r v i v a l under heavy g r a z i n g may i n d i c a t e t h a t the p l a n t i s u n u s u a l l y r e s i s t a n t t o g r a z i n g , t r a m p l i n g , or t h a t • - 33 -i t i s u n p a l a t a b l e t h r o u g h o u t a l l or p a r t o f the g r a z i n g season. (a) I n d i c a t o r s of Range Forage D e t e r i o r a t i o n i n Western Morth America  Range i n d i c a t o r s p r o v i d e the means of a s s e s s i n g range c o n d i t i o n s and range happenings (217). They i n d i c a t e the p h y s i o l o g i c a l c o n d i t i o n of an a s s o c i a t i o n and the changes i n t h e s o i l . Range i n d i c a t o r s may be used t o i n t e r p r e t v a r y i n g degrees of o v e r g r a z i n g . However, u n l e s s the term i s q u a l i f i e d , i t s a p p l i c a t i o n may become err o n e o u s f o r d e s t r u c -t i v e o v e r g r a z i n g may o n l y be one of the c o n t r i b u t o r y f a c t o r s l e a d i n g to range d e t e r i o r a t i o n . These range i n d i c a t o r s a r e e x c e e d i n g l y i m p o r t a n t i n r e c o g n i z i n g the i n i t i a l d e c l i n e o r r i s e i n range f o r a g e c o n d i t i o n . A c c o r d i n g t o T a l b o t (217), i n d i c a t o r s of range d e t e r i o r -a t i o n may be d i v i d e d i n t o s e v e r a l g roups, namely, range d e t e r i o r a t i o n w e l l under way, e v i d e n c e of p a s t damage to the range, i n d i c a t o r s of u n s a t i s f a c t o r y s o i l c o n d i t i o n s , and d o u b t f u l i n d i c a t o r s of range c o n d i t i o n s . Sampson (175) sum-m a r i z e s t h e s e p o i n t s as f o l l o w s : Range d e t e r i o r a t i o n w e l l under way i s shown by weakened v i t a l i t y of t h e p r i n c i p l e f o r a g e s p e c i e s , l i m i t e d , or the absence of r e p r o d u c t i o n of the most p a l a t a b l e s p e c i e s , c l o s e g r a z i n g of s p e c i e s o f low p a l a t a b i l i t y , a t h i n n i n g ground co v e r of the e n t i r e v e g e t a t i o n , replacement of t h e good f o r a g e p l a n t s by those r e g a r d e d as of l i t t l e v a l u e , e v i d e n c e of r e l i c t f o r a g e p l a n t s , i n c i p i e n t g u l l y i n g and e v i d e n c e of - 34 -i n c r e a s i n g s o i l e r o s i o n . E v i d e n c e s of p a s t range damage are* a r e l a t i v e absence of f o r m e r l y abundant f o r a g e p l a n t s , f o l i a g e and branches of the t a l l e r browse p l a n t s trimmed back as h i g h as the a n i m a l s can r e a c h , dead remnants of the browse s p e c i e s o f low s t a t u r e , abnormal abundance of those s p e c i e s which p e r s i s t and r e p r o -duce a f t e r more p a l a t a b l e s p e c i e s have d i s a p p e a r e d , and a c c e l e r a t e d s o i l e r o s i o n accompanied by g u l l y i n g . I n d i c a t o r s r e s u l t i n g p r i n c i p a l l y from u n s a t i s f a c t o r y s o i l c o n d i t i o n s as a r e s u l t of o v e r g r a z i n g a r e g i v e n i n S e c t i o n IV but may be b r i e f l y mentioned as those found i n c o n j u n c t i o n w i t h o t h e r i n d i c a t o r s . These a r e : a l a c k of a normal amount of o r g a n i c m a t t e r between groups of herbs or s h r u b s , an i n c o m p l e t e s o i l p r o f i l e w i t h the p o s s i b l e absence of t h e A Q and A - ^ l a y e r s , and the c o n s p i c u o u s presence of bunch g r a s s hummocks, i n d i c a t i n g g e n e r a l sheet e r o s i o n i n the absence of g u l l i e s . • D o u b t f u l or l e s s r e l i a b l e i n d i c a t o r s of a d e t e r i o r a t i n g range a r e l o c a l d e n u d a t i o n of t h e s o i l , sometimes caused by s l i p p i n g or d i s p l a c e m e n t , or by c o n g r e g a t i o n of g r a z i n g a n i m a l s on a r e s t r i c t e d a r e a ; i n c r e a s e s i n p o i s o n o u s p l a n t s r e s u l t i n g from a f a v o r a b l e s u c c e s s i o n a l r e a c t i o n ; g e n e r a l appearance and c o n d i t i o n of the g r a z i n g a n i m a l s , as where o v e r s t o c k i n g of an ar e a f o r a s i n g l e season i s t h e p r i n c i p a l c o n t r i b u t i n g f a c t o r ; and c o n d i t i o n o f the t i m b e r r e p r o d u c t i o n . The f o r a g e i n d i c a t o r s used t o determine the degree o f g r a z i n g v a r y w i t h the l o c a l a r e a s and i n d i v i d u a l p l a n t F i g u r e 6» P a s t u r e sage. An i n d i c a t i o n of l o n g c o n t i n u e d o v e r g r a z i n g of the r a n g e l a n d s of Southern Saskatchewan. a s s o c i a t i o n s w i t h i n t h e s e a r e a s . In n o r t h e r n A r i z o n a , A r i z o n a f e s c u e ( F e s t u c a a r i z o n i c a V a s e y H ) and mountain muhly Muhlembergia montana N u t t . ) s e r v e as i n d i c a t o r s of o v e r -g r a z i n g (6l). C l a r k e (45) s t u d i e d s h o r t g r a s s a r e a s i n s o u t h e r n A l b e r t a and Saskatchewan which were s i m i l a r i n a l l r e s p e c t s except the i n t e n s i t y of g r a z i n g . He found t h a t i n o v e r g r a z e d p a s t u r e s n e e d l e and t h r e a d g r a s s ( S t i p a comata T r i n . ) , June g r a s s ( K o e l e r i a g r a c i l i s P e r s . ) and b l u e g r a s s s p e c i e s (Poa spp.) were among the f i r s t t o be e l i m i n a t e d . I n d i c a t o r s of o v e r g r a z i n g were broom-weed ( G u t i e r r i z i a s a r o -t h r a e B r i t t . and Rushy) and p r a i r i e sage ( A r t e m i s i a f r i g i d a W i l l d . ) . J a r d i n e and Anderson (120) c l a s s i f y i n d i c a t o r s of o v e r -g r a z i n g as f o l l o w s : 1. Predominance o f a n n u a l weeds and g r a s s e s 2. Predominance of weeds and shrubs of l i t t l e or no v a l u e t o l i v e s t o c k 3. Dead or p a r t l y dead stumps of shrubs 4. N o t i c e a b l e damage t o t r e e r e p r o d u c t i o n 5. E r o s i o n and b a r r e n n e s s They s t a t e t h a t t h e s e i n d i c a t o r s a r e r e l a t i v e l y more i n d i c a -t i v e of sheep t h a n of c a t t l e damage. However, when o v e r -g r a z i n g r e a c h e s the s t a g e t h a t i t can be r e c o g n i z e d by t h e s e symptoms the appearance of t h e d e t e r i o r a t i n g range i s v e r y s i m i l a r f o r both c l a s s e s o f s t o c k . Daubenmire (65, 66) i n s t u d y i n g t h e e f f e c t of o v e r g r a z i n g on the bunchgrass areas of n o r t h w e s t e r n U n i t e d S t a t e s found t h a t i n near v i r g i n s t a n d s , on a d r y m a t t e r b a s i s at. t h e t i m e HThe a u t h o r i t y f o r the b o t a n i c a l names w i l l o n l y be g i v e n t h e f i r s t time mentioned. - 37 -of maximum growth, the f o r a g e a s s o c i a t i o n was 85 p e r c e n t bluebunch weatgrass ( A g r o p y r o n s p i c a t u m P u r s h . ) , 5 p e r c e n t Saridberg's b l u e g r a s s (Poa secunda P r e s l . ) , and 5 p e r c e n t c h e a t g r a s s (Bromus t e c t o r u m L . ) . As t h e i n t e n s i t y of g r a z i n g i n c r e a s e s , bluebunch wheatgrass ( A g r o p y r o n spicatum) i s g r a d u a l l y r e p l a c e d , m o s t l y by s m a l l u n p a l a t a b l e d i c o t y l e d o n s . I f the «native p r a i r i e i s g r a z e d o n l y d u r i n g f a l l and w i n t e r , t h e v e g e t a t i o n i s o n l y s l i g h t l y a l t e r e d . O b s e r v a t i o n s , made i n Utah (159) showed t h a t t h e areas of s p r i n g - f a l l ranges l o n g p r o t e c t e d from g r a z i n g and f i r e s u p p o r t a good co v e r of p l a n t s p a l a t a b l e to l i v e s t o c k . The c h i e f f o r a g e p l a n t s on t h e s e a r e a s i n c l u d e h i g h l y p a l a t a b l e p e r e n n i a l g r a s s e s , c h i e f l y bluebunch wheatgrass (Agropyron  s p i c a t u m ) . b e a r d l e s s wheatgrass ( A g r o p y r o n inerme Rydb.), b l u e s t e m wheatgrass (Agropyron S m i t h i i Rybd.) and Sandberg's b l u e g r a s s (Poa secunda). P e r e n n i a l g r a s s e s r e p r e s e n t 49 t o 81 p e r c e n t of the t o t a l p l a n t c o v e r . Sagebrush ( A r t i m e s i a  t r i d e n t a t a N u t t . ) i s u n i m p o r t a n t i n such a r e a s , o c c u p y i n g an average o f s l i g h t l y l e s s t h a n 10 p e r c e n t of t h e p l a n t c o v e r . Annual g r a s s e s , p r i n c i p a l l y downy brome or c h e a t g r a s s (Bromus  t e c t o r u m ) weeds, and shrubs o t h e r than sagebrush, are a l l r e l a t i v e l y u n i m p o r t a n t . O b s e r v a t i o n s on s i m i l a r a r e a s t h a t have been s u b j e c t e d t o heavy g r a z i n g showed i n e v e r y case a s e r i o u s d e p l e t i o n of p e r e n n i a l g r a s s e s , a d e c i d e d i n c r e a s e i n d e n s i t y of s a g e b r u s h , i n some cases a s h a r p i n c r e a s e i n t h e d e n s i t y of poor p e r e n n i a l weeds and annual g r a s s e s , and a d e c r e a s e i n t h e t o t a l p l a n t - 38 -d e n s i t y . These v e g e t a t i o n a l changes have r e s u l t e d i n r e d u c -t i o n s of 40 t o 75 p e r c e n t i n the c a r r y i n g c a p a c i t y of the areas s t u d i e d . Throughout the l i t e r a t u r e t h e r e a r e many papers d e a l i n g w i t h the i n d i c a t o r s of o v e r g r a z i n g and range c o n d i t i o n s i n every major r e g i o n and i n almost e v e r y d i s t r i c t . These papers and d i s c u s s i o n s by such noted a u t h o r i t i e s as Weaver, A l b e r t -son and o t h e r s (223, 240, 237, 246, 248, 1, 2, 3) i n t h e t a l l g r a s s and s h o r t g r a s s areas of Kansas, Nebraska and the s u r -r o u n d i n g a r e a s ; C l a r k e , T i s d a l e and Campbell (34, 37, 3 8 , 3 9 , 45, 46, 47, 228) i n t h e range a r e a s of w e s t e r n Canada; Dauben-mire ( 6 6 , 65, 67) i n t h e P a l o u s e areas of n o r t h w e s t e r n U n i t e d S t a t e s ; Sampson and Barnes i n C a l i f o r n i a (175, 176, 11, 174) and S t o d d a r t and Hanson i n Utah (211, 212, 214, 213, 100, 99, 98) have a l l made noted c o n t r i b u t i o n s i n t h e i r r e s p e c t i v e areas and t o s t u d i e s of range management i n g e n e r a l . I t i s i m p o s s i b l e , at t h i s p o i n t , t o p r e s e n t an adequate d i s c u s s i o n and a n a l y s i s of t h e s e p a p e r s . However, a s h o r t d i s c u s s i o n of the e f f e c t s o f o v e r g r a z i n g on the r a n g e l a n d v e g e t a t i o n of s o u t h e r n B r i t i s h Columbia w i l l g i v e some i n d i c a t i o n of t h e e f f e c t s of o v e r g r a z i n g on the c l i m a x s p e c i e s of t h e Lower, M i d d l e and Upper G r a s s l a n d a r e a s . .1 (b) I n d i c a t o r s of Range Forage D e t e r i o r a t i o n i n I n t e r i o r B r i t i s h Columbia  The g r a s s l a n d s of s o u t h e r n B r i t i s h Columbia may be found i n the v a l l e y s o f t h e i n t e r i o r and on the s u r r o u n d i n g h i l l s i d e s . The a l t i t u d e of t h e s e a r e a s v a r i e s from 1000 t o a p p r o x i m a t e l y 3000 f e e t above sea l e v e l . The t o t a l e x t e n t of th e s e g r a s s l a n d s i n c l u d e a p p r o x i m a t e l y 3 t o 4 m i l l i o n a c r e s (227) and c o n s t i t u t e s t h e b a s i s f o r t h e g r a z i n g i n d u s t r y of t h i s p r o v i n c e . The c l i m a t e of the open or g r a s s l a n d ranges i s r e l a t i v e l y warm and d r y . T h i s may be shown i n Table I . TABLE I Average Annual P r e c i p i t a t i o n and Temperature of Centers i n the G r a s s l a n d Areas of B.C. (227) ~" AVE. MEAN TEMPERATURE PLACE ZONE ANNUAL ; PPT. J u l y J a n u a r y T r a n q u i l l e Lower G r a s s l a n d 8 .0" 70° 2 5 ° A s h c r o f t " " 6 . 9 " No Record No Record M e r r i t t " " 8 . 6 " 64° 2 2 ° Vernon Upper " 15.2" 68° 23° Vavenby Montane F o r e s t 1 4 . 5 " 6 3 0 1 9 ° B i g Creek " " 12.2" 56° 1 5 ° The s o i l s v a r y from Brown t o B l a c k ( 2 0 6 ) , each;type b e i n g a s s o c i a t e d w i t h one of the p r i n c i p a l g r a s s l a n d a s s o c i a t i o n s . The v e g e t a t i o n i s d i v i d e d i n t o t h r e e r e l a t i v e l y d i s t i n c t zones i n the g r a s s l a n d s which g i v e way t o t h e Montane F o r e s t which i s used f o r summer and e a r l y f a l l g r a z i n g o n l y . The A g r o p y r o n - A r t i m e s i a a s s o c i a t i o n i s found on t h e Brown s o i l s of the Lower G r a s s l a n d s . the c l i m a x v e g e t a t i o n of t h i s a r e a was composed o f a spa r s e ground c o v e r of bluebunch wheat-.grass (Agropyron s p i c a t u m ) . Sandberg's b l u e g r a s s (Poa secunda). sagebrush ( A r t i m e s i a t r i d e n t a t a ) and a few p e r e n n i a l f o r b s . - 40 -V e r y l i t t l e of t h e a r e a remains i n c l i m a x v e g e t a t i o n , b e i n g dominated by such s u c c e s s i o n a l p l a n t s as sagebrush ( A r t e m i s i a  t r i d e n t a t a ) and o t h e r semi d e s e r t shrubs.and p l a n t s ( 2 2 8 ) . F i g u r e 8. S e r i o u s O v e r g r a z i n g on the Lower G r a s s -l a n d s near Kamloops, B.C. r e s u l t e d i n t h i s E x c e s s i v e Stand of Sagebrush. On t h e s a n d i e r s l o p e s t h e dominant s p e c i e s i n c l u d e n e e d l e and t h r e a d g r a s s ( S t i p a comata). sand dropseed ( S p o r o b o l u s c r y p -t a n d r u s A. G r a y ) , and r a b b i t b r u s h (Crysothamnus nauseosus P a l l . ) The M i d d l e G r a s s l a n d s are dominated i n the c l i m a x stage by the Agropyron-Poa a s s o c i a t i o n . T his type of g r a s s l a n d i s a s s o c i a t e d w i t h Dark Brown s o i l s . The p r i n c i p a l s p e c i e s of t h i s c l i m a x t y p e are bluebunch wheatgrass (Agropyron spicatum) f o l l o w e d by Sandberg's b l u e g r a s s (Poa s e c u n d a ) . T i s d a l e - 4 1 -r e p o r t s (228) t h a t i n t h e c l i m a x , shrubs are l i m i t e d t o one s p e c i e s , t h a t b e i n g r a b b i t b rush (Crysothamnus n a u s e o s u s ) . Under c o n d i t i o n s of severe g r a z i n g t h i s a s s o c i a t i o n has g i v e n way t o two communities. The f i r s t i s dominated by n e e d l e and t h r e a d g r a s s ( S t i p a comata). The c l i m a x s p e c i e s bluebunch wheatgrass (Agropyron s p i c a t u m ) and Sandberg's b l u e g r a s s (Poa secunda) are s t i l l r e p r e s e n t e d i n t h e a s s o c i a t i o n but i n reduced p r o p o r t i o n s . Annual s p e c i e s such as c h e a t g r a s s (Bromus t e c t o r u m ) and l i t t l e b l u e b u r ( L a p p u l a o c c i d e n t a l i s Greene) are p r e s e n t i n r e l a t i v e l y l a r g e r numbers t h a n i n t h e c l i m a x a s s o c i a t i o n . The second community i s dominated by c h e a t g r a s s (Bromus t e c t o r u m ) . These a r e a s v a r y i n s i z e s F i g u r e 9. M i d d l e G r a s s l a n d s between Pass Lake and Kamloops, B.C. Note th e topography and r e s e a r c h e n c l o s u r e . - 42 -up t o as much as two or t h r e e square m i l e s (227) o f the M i d d l e G r a s s l a n d s . This i s p a r t i c u l a r l y n o t i c e a b l e i n t h e N i c o l a and Thompson V a l l e y s . T h i s community_has deve l o p e d from t h e p r e v i o u s l y S t i p a - A g r o p y r o n - P o a type as a r e s u l t of c o n t i n u o u s o v e r g r a z i n g . The p l a n t s of t h e c l i m a x a s s o c i a t i o n t h a t s u r -v i v e d have become s m a l l , l a c k i n g b o t h i n b a s a l a r e a and v i g o r . The Upper G r a s s l a n d s are dominated i n the c l i m a x a s s o c i -a t i o n by bluebunch wheatgrass (Agropyron s p i c a t u m ) and rough f e s c u e ( F e s t u c a s c a b r e l l a T o r r . ) . This a r e a rec.ieves more m o i s t u r e per annum tha n does e i t h e r of the o t h e r two zones and the s o i l s a r e c l a s s e d as p a r t of t h e B l a c k S o i l zone (2 0 6 ) . The c l i m a x a s s o c i a t i o n c o n t a i n s two poisonous p l a n t s , t w o - c o l o u r e d l a r k s p u r ( D e l p h i n i u m b i c o l o u r N u t t . ) and death camus (Zygadenus venerosus S. W a t t ) . As i n t h e case of t h e middle g r a s s l a n d , severe g r a z i n g has r e s u l t e d i n the e v o l u -t i o n t o two major Upper G r a s s l a n d communities. These have been i d e n t i f i e d (228) as t h e S t i p a - P o a and t h e Poa-Bromus communities. A l a r g e p o r t i o n o f t h e Upper G r a s s l a n d zone i s o c c u p i e d by the S t i p a - P o a community, w h i c h i s dominated by two p e r e n n i a l g r a s s e s , Columbia n e e d l e g r a s s ( S t i p a Columbi-ana Macoun) and Kentucky b l u e g r a s s (Poa p r a t e n s i s L . ) . N e i t h e r of t h e s e g r a s s e s a r e abundant i n the c l i m a x a s s o c i a -t i o n . Kentucky b l u e g r a s s (Poa p r a t e n s i s ) i s found c h i e f l y ( 2 0 6 ) on a r e a s t h a t were somewhat s h e l t e r e d and where the s o i l s were f i n e and deep. Columbia n e e d l e g r a s s ( S t i p a  Columbiana) was found to dominate i n a r e a s t h a t were more exposed and where the s o i l was c o a r s e r . Balsam r o o t - 43 -( B a l s a m o r h i z a s a g i t t a t a N u t t . ) and ghost's beard (Tragopogon p r a t e n s i s L.) are two of t h e f o r b s commonly found i n t h i s community. The Poa-Bromus community i s u s u a l l y dominated by Sand-berg's b l u e g r a s s (Poa secunda). but c h e a t g r a s s (Bromus t e c -torum) i s dominant i n some a r e a s w h i l e b e i n g much l e s s i m p o r t a n t i n o t h e r s . T h i s community i s produced under con-d i t i o n s of severe g r a z i n g . Not o n l y are the main g r a s s e s but a l s o many t a l l - g r o w i n g f o r b s of t h e A g r o p y r o n - F e s t u c a c l i m a x and the S t i p a - P o a community are r a r e or l a c k i n g i n t h e Poa-Bromus type.. Many of t h e s e p l a n t s , w h i l e not eaten t o any e x t e n t on m o d e r a t e l y g r a z e d l a n d s , are g r a z e d r e a d i l y on o v e r s t o c k e d ranges and t h e i r p o p u l a t i o n s c o n s e q u e n t l y become markedly r e d u c e d . I t may be seen t h a t t h e v e g e t a t i o n of t h e s o u t h e r n i n t e r i o r of B r i t i s h Columbia i s q u i t e comparable t o some of t h e range areas i n the s t a t e s of Washington.,...Oregon, Idaho and Utah. Bluebunch wheatgrass (Agropyron s p i c a t u m ) i s common thro u g h o u t t h e s e a r e a s as i t i s the presence and r e l a t i v e abundance of s p e c i e s such as sagebrush ( A r t e m i s i a  t r i d e n t a t a ) , r a b b i t b r u s h (Crysothamnus nauseosus) and balsam r o o t ( B a l s a m o r h i z a s a g i t t a t a ) . ( c ) I n d i c a t o r s of Pro p e r Forage U t i l i z a t i o n The c a r r y i n g c a p a c i t y of semi a r i d g r a s s l a n d such as range i s low compared w i t h p a s t u r e s under more humid con-d i t i o n s and i n a d d i t i o n , the p r i n c i p l e s of g r a z i n g manage-ment d i f f e r . Great areas of range have been r u i n e d by - 44 -o v e r g r a z i n g , due e i t h e r t o o v e r s t o c k i n g of the e n t i r e a r e a or t o b a d l y d i s t r i b u t e d s t o c k i n g consequent upon i n a d e q u a t e management. The r e s u l t s a r e a g a i n a d e t e r i o r a t i o n of t h e o r i g i n a l v e g e t a t i o n under t h e c o n s t a n t g r a z i n g and t r a i l i n g of s t o c k , t h r o u g h the e c o l o g i c a l s t a g e s of r e t r o g r e s s i o n c h a r a c t e r i z e d by t h e development of p o o r e r t y p e s of p e r e n n i a l g r a s s e s , a n n u a l g r a s s e s , weeds and i n some cases bushes and s c r u b . In o r d e r t o m a i n t a i n range f o r a g e p r o d u c t i o n a t i t s h i g h e s t l e v e l , and r e s t o r e d e p l e t e d ranges, t h e b e t t e r f o r a g e p l a n t s must be p r o p e r l y u s e d . But what i s p r o p e r use? The answer r e q u i r e s a knowledge of t h e r e s i s t a n c e t o g r a z i n g of s e v e r a l hundred s p e c i e s which f u r n i s h b o t h t h e b u l k of t h e f e e d and watershed p r o t e c t i o n . However, i n a l a n d t h a t r e q u i r e s 20 t o 100 or more a c r e s to support a cow on a y e a r -l o n g b a s i s ( 3 5 ) , the a r e a t h a t can be i n s p e c t e d w i t h n e c e s s a r y f r e q u e n c y by one stockman i s so s m a l l a p r o p o r t i o n of the whole t h a t the a c t u a l degree of u t i l i z a t i o n eaqh season i s n e c e s s a r i l y v e r y d i f f i c u l t t o d e t e r m i n e . In f a c t , e x cept on v e r y s m a l l s t u d y p l o t s , or p a s t u r e s , the degree of u t i l i z a -t i o n i s commonly based e n t i r e l y on judgment a c q u i r e d from e x p e r i e n c e . But where c o n t i n u e d p r o d u c t i v i t y o r g r a d u a l death o f a good f o r a g e g r a s s may depend upon a d i f f e r e n c e i n f o l i a g e removal of as l i t t l e as 10 p e r c e n t , a more a c c u r a t e measurement i s n e c e s s a r y . T a l b o t (217) found t h a t i n d i c a t o r s of s a t i s f a c t o r y range f o r a g e use a r e : - 45 -( i ) v i g o r o u s appearance and l u x u r i a n c e o f the f o r a g e s t a n d ; ( i i ) absence of a c c e l e r a t e d s o i l w a shing; ( i i i ) s l i g h t or no use of u n p a l a t a b l e s p e c i e s ; ( i v ) l a c k of e x t e n s i v e a r e a s o v e r r u n by p a l a t a b l e p l a n t s ; ( v ) absence of s e r i o u s i n j u r y t o t i m b e r r e p r o d u c t i o n . D e p l e t e d ranges and ranges i n v a r y i n g degrees of d e t e r i o r a t i o n show improvement w i t h t h e t h i c k e n i n g of the s t a n d of t h e d e s i r a b l e f o r a g e s p e c i e s and when g u l l i e s a r e b e i n g n a t u r a l l y r e c l a i m e d . An i n f i n i t e number of q u e s t i o n s must be answered i n s e t t i n g up u t i l i z a t i o n st.andards f o r any p a r t i c u l a r range u n i t s . For example, what are the s p e c i e s t h a t do or s h o u l d f u r n i s h most of the f o r a g e a t d i f f e r e n t seasons of the yea r ? What are t h e i r l i f e h i s t o r i e s , and how do t h e d i f f e r e n t c l a s s e s of s t o c k r e l i s h them? What i s t h e n a t u r a l p l a n t s u c c e s s i o n , how i s i t a f f e c t e d by o v e r g r a z i n g and the v a r i o u s o t h e r degrees of u t i l i z a t i o n , and what s t a g e can or s h o u l d be m a i n t a i n e d under g r a z i n g use? Even when prop e r u t i l i z a t i o n has been determined f o r a s p e c i e s or g r a z i n g a s s o c i a t i o n under one s e t of c o n d i t i o n s , what adjus t m e n t s must be made when t h e a s s o c i a t i o n i s s e v e r e l y d e p l e t e d , and what p r e c a u t i o n s a re n e c e s s a r y f o r extreme drought or where s p e c i a l l a n d s e r v i c e s such as watershed p r o t e c t i o n , t i m b e r p r o d u c t i o n , or w i l d l i f e a r e i m p o r t a n t or dominait? These problems are e s p e c i a l l y d i f f i c u l t as a r e s u l t of - 46 -the range re source,. b oth as t o c o m p o s i t i o n , form, h a b i t a t , and i n p r o d u c t i o n , one y e a r w i t h a n o t h e r . (2) C l a s s i f i c a t i o n of V e g e t a t i o n f o r D e t e r m i n i n g t h e Degree of O v e r g r a z i n g  The r e c o g n i t i o n of range c o n d i t i o n i s f a c i l i t a t e d by an a c c u r a t e a n a l y s i s of t h e v e g e t a t i o n and t h e degree of d e t e r -i o r a t i o n from th e c l i m a x a s s o c i a t i o n or t h e h i g h e s t t y p e of v e g e t a t i o n the a r e a would n a t u r a l l y s u p p o r t ; the p r e s c r i p t i o n of c o r r e c t i v e measures r e q u i r e s t h a t the v a r i o u s degrees of d e t e r i o r a t i o n or range c o n d i t i o n must be c l a s s i f i e d . A m o d i f i c a t i o n of s i x c o n d i t i o n c l a s s e s used i n range i n v e s t i g a t i o n by the S o i l C o n s e r v a t i o n S e r v i c e i n the P a c i f i c Northwest of the U n i t e d S t a t e s i s now p r e s e n t e d . These c l a s s e s can be a p p l i e d to c o n d i t i o n s i n B r i t i s h Columbia to determine p r e s e n t or past use. Range c l a s s i f i c a t i o n s of any k i n d s h o u l d be based on p l a n t s p e c i e s s u b j e c t t o l i v e s t o c k u t i l i z a t i o n as the c l a s s i f i c a t i o n i s d e s i g n e d p r i m a r i l y t o f a c i l i t a t e c o r r e c t g r a z i n g use of the f o r a g e s p e c i e s . (a) E x c e l l e n t or C l a s s A C o n d i t i o n T h i s c l a s s i s composed of c l i m a x a s s o c i a t i o n s f o r t h e most p a r t w i t h l i t t l e or no r e p l a c e m e n t by an i n t r o d u c t i o n of n o n - c l i m a x s p e c i e s . The s p e c i e s t h a t were f o r m e r l y domin-ant over t h e e n t i r e r a n g e l a n d of B r i t i s h Columbia w i l l s t i l l occur as dominants i n e x c e l l e n t range and w i l l o c cur i n e s s e n t i a l l y t h e i r o r i g i n a l abundance. In the o t h e r c l a s s e s t o be d i s c u s s e d the r e l a t i v e abundance of t h e s e s p e c i e s w i l l - 47 -have been m o d i f i e d , or t h e y w i l l have been e l i m i n a t e d and r e p l a c e d by p l a n t s l o w e r i n . t h e s u c c e s s i o n . I n d i c a t o r s of t h i s c l a s s , i n t h e Lower G r a s s l a n d s of B r i t i s h Columbia, w i l l be such p l a n t s as bluebunch wheatgrass (Agropyron s p i c a t u m ) and Sandberg's b l u e g r a s s (Poa secunda). A range i n e x c e l l e n t c o n d i t i o n w i l l have been r a r e l y i f ever o v e r g r a z e d e i t h e r s e a s o n a l l y , by a p a r t i c u l a r c l a s s o f s t o c k , or y e a r l o n g . I f o v e r g r a z i n g has been p r e s e n t i t w i l l have been of s h o r t d u r a t i o n o n l y . Under t h e s e c o n d i t i o n s i t i s e v i d e n t t h a t t h e r e i s adequate s a l t and water a v a i l a b l e and t h a t good management p r i n c i p l e s a r e i n f o r c e . L i t t l e o r no m o d i f i c a t i o n of t h e g r a z i n g system employed need be u n d e r t a k e n . No r u n - o f f c o n t r o l measures need t o be t a k e n on ranges i n t h i s c o n d i t i o n . (b) Good or C l a s s B C o n d i t i o n In t h i s c l a s s , c l i m a x s p e c i e s s t i l l form t h e b u l k of the p l a n t c o v e r , but t h e r e are some n o n - c l i m a x s p e c i e s p r e s e n t i n the a s s o c i a t i o n s . One or some of the dominants i n the c l i m a x a s s o c i a t i o n may have r e p l a c e d o t h e r members o f the a s s o c i a t i o n . For example, i n B r i t i s h Columbia Lower G r a s s l a n d s , bluebunch wheatgrass (Agropyron s p i c a t u m ) and Sandberg's b l u e g r a s s (Poa secunda) w i l l s t i l l p redominate. However, c h e a t g r a s s (Bromus t e c t o r u m ) w i l l be e v i d e n t i n some l o c a l i t i e s as w e l l as sagebrush ( A r t i m e s i a t r i d e n t a t a ) . Sandberg's b l u e g r a s s (Poa secunda) w i l l u s u a l l y be more abundant than on C l a s s A r a n g e s , but under c e r t a i n t y p e s of g r a z i n g ( c l a s s o v e r g r a z i n g by sheep) i t may be c o m p l e t e l y - 48 -r e p l a c e d by bluebunch wheatgrass ( 1 1 5 ) . A range i n t h i s c o n d i t i o n i s not c o n s i d e r e d o v e r g r a z e d but when i t does occur i t i s t h e r e s u l t of o v e r e s t i m a t i o n of the g r a z i n g c a p a c i t y , the wrong c l a s s o f s t o c k or a temporary s h o r t a g e of f e e d d u r i n g a drought. C o r r e c t i o n of the f a u l t w i l l be s u f f i c i e n t t o remedy t h i s overuse and f u r t h e r d e t e r -i o r a t i o n w i l l be p r e v e n t e d . These ranges w i l l r e q u i r e few or no r e m e d i a l measures except o c c a s i o n a l minor m o d i f i c a t i o n s of some phases of management i n water r e t a r d a t i o n and f l o o d c o n t r o l . ( c ) F a i r or C l a s s C C o n d i t i o n Under f a i r c o n d i t i o n , the c l i m a x a s s o c i a t i o n i s showing s i g n s of d e p l e t i o n and a r a t h e r heavy i n f e s t a t i o n of annuals and n o n - c l i m a x p e r e n n i a l s i s e v i d e n t . A s u b - c l i m a x s p e c i e s may or may not have become dominant. Under t h e s e c o n d i t i o n s - t h e bluebunch wheatgrass (Agropyron s p i c a t u m ) w i l l be d e f i n i t e l y weakened and Sandberg's b l u e g r a s s (Poa  secunda) may or may not have s u f f e r e d as w e l l . C h e a t g r a s s (Bromus tectorum)- w i l l be farumore p l e n t i f u l t h a n on good ranges and i n some areas sagebrush ( A r t e m i s i a t e c t o r u m ) or r a b b i t b r u s h (Crysothamnus nauseosus,) w i l l be p r e s e n t a f f e c t -i n g b o th the appearance and the c a r r y i n g c a p a c i t y of t h e range. A range i n f a i r c o n d i t i o n w i l l be c o n s i d e r e d o v e r g r a z e d and one or more of such c a r d i n a l p r i n c i p l e s of good range management as proper s e a s o n a l use, proper numbers, pro p e r - 49 -c l a s s of s t o c k , and proper d i s t r i b u t i o n , w i l l have been v i o l a t e d . T h i s c o n d i t i o n may be the r e s u l t of dr o u g h t , but i n B r i t i s h Columbia i t w i l l p r o b a b l y i n d i c a t e e i t h e r an o v e r -e s t i m a t i o n of the amount of f o r a g e a v a i l a b l e , t h e wrong c l a s s of l i v e s t o c k , t oo e a r l y s p r i n g g r a z i n g , or t h e f a i l u r e t o remove the s t o c k from s p r i n g p a s t u r e s soon enough t o p e r m i t seed p r o d u c t i o n . On C l a s s C ranges, which a re found t o be graze d by the r i g h t number of s t o c k , a v a r i a t i o n i n the g r a z i n g system must be i n t r o d u c e d . I t i s not uncommon t o f i n d f a i r range i n t e r s p e r s e d among areas of o t h e r w i s e good or e x c e l l e n t c o n d i t i o n . I n t h i s event a c l o s e s c r u t i n y o f the management p r a c t i c e s must be u n d e r t a k e n and c o r r e c t i v e measures a p p l i e d . I n most cases i t w i l l be found t h a t the t r o u b l e l i e s i n poor d i s t r i b u t i o n of the s t o c k as a r e s u l t of inade q u a t e b e r d i n g , w a t e r i n g f a c i l i t i e s or improper s a l t i n g . Ranges i n f a i r c o n d i t i o n s h o u l d not be g r a z e d t o f u l l c a p a c i t y but s h o u l d be g i v e n a s a f e t y margin to a l l o w r e c o v e r y . I f t h i s i s not p e r m i t t e d , the r a m i f i c a t i o n s of o v e r g r a z i n g w i l l r e s u l t . These ranges w i l l u s u a l l y c a l l f o r check dams or o t h e r l o c a l i z e d f l o o d c o n t r o l s . (d) Poor or C l a s s D C o n d i t i o n Under t h e s e c o n d i t i o n s a major p o r t i o n of the p l a n t a s s o c i a t i o n i s composed of s u b - c l i m a x s p e c i e s w h i l e under c o n d i t i o n s of accompanying t o p s o i l e r o s i o n b o t h t h e s e and the c l i m a x s p e c i e s may be l a c k i n g . Bluebunch wheatgrass (Agropyron s p i c a t u m ) , a l t h o u g h u s u a l l y s t i l l p r e s e n t , w i l l be - 50 -s c a t t e r e d and b a d l y s t u n t e d p l a n t s . The ground w i l l appear t o be c o v e r e d w i t h c h e a t g r a s s (Bromus tectorum ) i n t e r s p e r s e d w i t h sagebrush ( A r t e m i s i a t r i d e n t a t a ) and r a b b i t b r u s h (Crysothamnus n a u s e o s u s ) • Rangeland i n t h i s c o n d i t i o n i s i n d i c a t i v e of l o n g , con-t i n u e d o v e r g r a z i n g and a g e n e r a l abuse of the p r i n c i p l e s of range management. A marked r e d u c t i o n i n l i v e s t o c k numbers, o f t e n c o u p l e d w i t h d r a s t i c changes i n the o t h e r management p r a c t i c e s , i s n e c e s s a r y i f t h e r a n g e l a n d i s t o be saved and r e c o v e r y u n d e r t a k e n . A r a t h e r heavy g r a z i n g of a n n u a l p l a n t s and g r a s s e s may be j u s t i f i e d i n the event t h a t such ranges c o n s t i t u t e a f i r e h a z a r d . However, c a r e must be t a k e n t o make sure t h a t the s t o c k i s removed as soon as the s t o c k b e g i n s to u t i l i z e the shoots o f p e r e n n i a l g r a s s e s . Reduced l i v e s t o c k numbers w i l l f a v o u r the d e s i r a b l e c l i m a x s p e c i e s , and u n l e s s e r o s i o n has removed the t o p s o i l (26), the c l i m a x p e r e n n i a l s w i l l r e t u r n t o comprise an e x c e l l e n t or good range w i t h consequent h i g h e r c a r r y i n g c a p a c i t y and g r e a t e r p r o t e c t i o n a g a i n s t e r o s i o n . F l o o d c o n t r o l on these ranges w i l l n e c e s s i t a t e d r a s t i c changes i n management p r a c t i c e s w i t h more f r e q u e n t i n s t a n c e s of s t r u c t u r a l c o n t r o l of l o c a l a r e a s . (e) Very Poor or C l a s s E C o n d i t i o n When ranges are c l a s s e d as v e r y poor, the c l i m a x v e g e t a t i o n i s absent w h i l e n o n - c l i m a x s p e c i e s , o f t e n u n p a l a t -a b l e , p o i s o n o u s , or m e c h a n i c a l l y i n j u r i o u s , predominate. - 51 -Under c o n d i t i o n s such as t h e s e i n i n t e r i o r B r i t i s h Columbia bluebunch wheatgrass (Agr o p y r o n spicatum) and Sandberg's b l u e g r a s s (Poa secunda) w i l l have d i s a p p e a r e d . C h e a t g r a s s (Bromus t e c t o r u m ) , R u s s i a n t h i s t l e ( S a l s o l a p e s t i f e r A. N e l l s J , tumblemustard ( N o r t a a l t i s s i m a L.) and sagebrush or r a b b i t b r ush w i l l dominate, a l t h o u g h t h e r e may be l a r g e amounts of bare ground, p a r t i c u l a r l y i n y e a r s of poor growing c o n d i t i o n s . Very poor rangers u s u a l l y i n d i c a t e l o n g - c o n t i n u e d o v e r -g r a z i n g by one c l a s s of l i v e s t o c k . T h i s c o n d i t i o n may a l s o be the r e s u l t o r , or be ag g r a v a t e d by improper s e a s o n a l or r o t a t i o n a l u se. I n g e n e r a l , ranges i n t h i s c o n d i t i o n s h o u l d be c l o s e d t o g r a z i n g of any type u r i i l t he c l i m a x s p e c i e s or d e s i r e d p e r e n n i a l s a r e p r e s e n t i n s u f f i c i e n t number t o p e r m i t a t l e a s t a c l a s s i f i c a t i o n of f a i r . L o c a l i z e d a r e a s showing a very poor c o n d i t i o n r e s u l t i n g f r om l o c a l c o n c e n t r a t i o n a s , f o r example, from t o o many s t o c k w a t e r i n g or s a l t i n g a t a g i v e n p o i n t , can u s u a l l y be c o r r e c t e d t h r o u g h t h e l o c a t i o n of a d d i t i o n a l s a l t i n g p o i n t s and water hcfles i n accordance w i t h the p r i n c i p l e s of good range management. I t may n e c e s s i t a t e the c l o s i n g of t h e w a t e r i n g h o l e s i n the s e c t i o n s of the range a r e a s f a l l i n g i n t o t h i s c l a s s i f i c a t i o n . S o i l l o s s e s from range i n t h i s c o n d i t i o n may be so severe as t o p r e v e n t o r i n d e f i n i t e l y d e l a y complete r e c o v e r y . T h i s f a c t o r must be c a r e f u l l y c o n s i d e r e d , both i n d e t e r -m i n i n g the r a t e of r e c o v e r y and r e v e g e t a t i o n by n a t i v e s p e c i e s and i n p r o j e c t s of a r t i f i c e d r e s e e d i n g . I f i n a f l o o d a r e a , t h e s e r a n g e s should be c l o s e d t o g r a z i n g t o - 52 -# f a c i l i t a t e s p e c i a l f l o o d treatment. 1 F i g u r e 1 0 . A w e l l managed watering place i n Southern Saskatchewan. Note the abundance of forage and the c o n d i t i o n of the l i v e s t o c k . Figure 1 1 . A p o o r l y managed watering place i n S o u t h e r n Saskatchewan. Note the denudation of the ground and poor c o n d i t i o n of the l i v e s t o c k - 53 -( f ) D e p l e t e d or C l a s s F C o n d i t i o n I n t o t h i s c l a s s f a l l n e a r l y deseeded a r e a s such as bed grounds and s t o c k t r a i l s t h a t a r e almost w o r t h l e s s f o r g r a z i n g because of extreme and r e p e a t e d abuse. The c l i m a x s p e c i e s bluebunch wheatgrass (Agro p y r o n spicatum) and Sand-berg's b l u e g r a s s (Poa secunda) w i l l have been k i l l e d o u t . Cheatgrass may be p r e s e n t but i n many p l a c e s i t w i l l have been removed e i t h e r by g r a z i n g or t r a m p l i n g . Sagebrush ( A r t e m i s i a t r i d e n t a t a ) and r a b b i t b r u s h (Crysothamnus nau-seosus) w i l l be s e v e r e l y g r a z e d , b r o k e n and t r a m p l e d by t h e s t o c k w h i l e R u s s i a n t h i s t l e ( S a l s o l a p e s t i f e r ) may e i t h e r be very abundant o r t e m p o r a r i l y removed by g r a z i n g . Seldom do a r e a s such as t h e s e r e s u l t from o v e r g r a z i n g a l o n e , b u t , i n p a r t , from e x c e s s i v e t r a m p l i n g and e r o s i o n as w e l l as f i r e . Where t h i s c o n d i t i o n e x i s t s on l i v e s t o c k d r i v e w a y s an a l t e r n a t e r o u t e s h o u l d be employed. The heavy c o n c e n t r a t i o n of s t o c k around w a t e r h o l e s can be remedied by p r o v i d i n g a d d i t i o n a l w a t e r i n g f a c i l i t i e s or by s a l t i n g and h e r d i n g so as to p r e v e n t u n n e c e s s a r y t r a m p l i n g and g r a z i n g i n the immediate v i c i n i t y of the w a t e r h o l e s . F i g u r e s 10 and 11 show the e f f e c t ot s t o c k on t h e vege-t a t i o n around two w a t e r i n g p l a c e s i n Saskatchewan. F i g u r e 10 shows a w a t e r i n g p l a c e c o n s t r u c t e d i n c o - o p e r a t i o n w i t h the P.F.R.A. and around w h i c h the p r i n c i p l e s of good range management have been a p p l i e d . F i g u r e 11 shows a w a t e r i n g p l a c e which i s t o o f a r removed from t h e next w a t e r h o l e . The s t o c k were p e r m i t t e d t o c o n c e n t r a t e i n the a r e a r e s u l t i n g i n - 54 -the v e r y e v i d e n t d e n u d a t i o n of the l a n d . I t i s w e l l t o p o i n t out t h a t the type and c o n s c i e n t i p u s n e s s of the r a n c h e r shows up i n h i s c a t t l e . In the p r o p e r l y managed range we see w e l l b r e d c a t t l e i n good c o n d i t i o n ; on t h e p o o r l y managed range the c a t t l e are of n o n - d e s c r i p t b r e e d i n g and are i n r e l a t i v e l y poor c o n d i t i o n . On F C l a s s a r e a s s t r u c t u r a l c o n t r o l and r e s e e d i n g w i l l be r e q u i r e d i n many cases t o e x p e d i t e r e c o v e r y and h a s t e n r e d u c t i o n of e x c e s s i v e s o i l and w a t e r l o s s e s . TABLE I I G r a z i n g C a p a c i t i e s of V a r i o u s C o n d i t i o n C l a s s e s on Open Grass and Shrub Ranges near Dayton, Washington (115) Range C o n d i t i o n G r a z i n g e a Type C l a s s Capacity/100 a c r e s ANIMAL UNIT MONTHS A 144 OPEN B 74 PATIT CREEK GRASS C 48 D 31 SHRUBS B 49 C 23 A 127 POMEROY OPEN B 80 GRASS C 37 D 23 W h i l e t h i s t a b l e was p r e p a r e d from d a t a g a t h e r e d i n Washington, th e g e n e r a l p l a n t a s s o c i a t i o n s are s i m i l a r t o those i n B r i t i s h Columbia. The v a r i o u s g r a z i n g c o n d i t i o n c l a s s e s have been summarized i n Table I I I . R e g a r d l e s s of the e x a c t cause o f o v e r g r a z i n g , the f i r s t s t e p i s to s t o p the type of misuse of the l a n d t h a t has caused TABLE I I I Summary of the E f f e c t of G r a z i n g on Bunch Grass Ranges (115) C o n d i t i o n P r e d o m i n a t i n g Management P r a c t i c e s R e v i s i o n s r e q u i r e d C l a s s V e g e t a t i o n R e s p o n s i b l e f o r C o n d i t i o n i n Present P r a c t i c e s E r o s i o n or F l o o d C o n t r o l Measures i n d i c a t e d  EXCELLENT CLASS A C l i m a x C o r r e c t numbers, c l a s s d i s t r i b u t i o n and s e a s o n a l use None C o n t i n u a t i o n of p r e s e n t manage-ment p r a c t i c e s GOOD CLASS B P r i m a r i l y c l i -max, non-c l i m a x p l a n t s b e g i n n i n g t o inv a d e N u m b e r s , c l a s s , d i s t r i b u -t i o n & s e a s o n a l use u s u a l l y c o r r e c t . C l a s s may o c c a s i o n a l l y be wrong' o r c a r r y i n g c a p a c i t y o v e r e s t i m a t e d None; s l i g h t r e -d u c t i o n i n numbers, or change i n c l a s s of s t o c k . A d o p t i o n of recommended management p r a c t i c e s FAIR CLASS C Cli m a x , but becoming de-pleted;; non-climax s p e c i e s becoming abundant U s u a l l y o v e r g r a z e d ; may be t h e wrong c l a s s of s t o c k ; m a l d i s t r i b u t i o n or wrong season of use R e d u c t i o n i n num-b e r s ; change of c l a s s ; change o f season or r e -d i s t r i b u t i o n A d o p t i o n of recom-mended management p r a c t i c e s . May r e q u i r e o c c a s i o n -a l s t r u c t u r a l c o n t r o l POOR CLASS D Clim a x , but s e r i o u s l y de-pleted.; non-climax s p e c i e s predominate Heavy or l o n g c o n t i n u e d o v e r g r a z i n g ; improper c l a s s of s t o c k ; mal-d i s t r i b u t i o n or wrong season of use D r a s t i c r e d u c t i o n i n numbers, or change i n c l a s s o f s t o c k . S e a s o n a l g r a z i n g of annuals to reduce fire hazard A d o p t i o n of recom-mended management p r a c t i c e s , o f t e n accompanied by some s t r u c t u r a l c o n t r o l & possibly r e s e e d i n g VERY POOR CLASS E Non-climax annuals and pe r e n n i a l s Severe o v e r g r a z i n g , wrong c l a s s of s t o c k , wrong season of use, o r improper d i s t r i b u t i o n C l o s e t o a l l g r a -z i n g except f o r r e s t r i c t e d s e a s o n a l use Severe o v e r g r a z i n g , wrong c l a s s of s t o c k , wrong season of use, t r a m p l i n g , or improper d i s t r i b u t i o n Close to aH grazing. Reseeding may be n e c e s s a r y . Some s t r u c t u r a l control u s u a l l y r e q u i r e d . DEPLETED CLASS F None or few n o n - c l i m a x s p e c i e s Cl o s e t o a l l g r a z i n g Close t o a l l g r a -z i n g . Reseeding and s t r u c t u r a l c o n t r o l u s u a l l y r e q u i r e d . - 56 -the t r o u b l e , whatever the cause may have been. T h i s immedi-a t e l y b r i n g s i n tie economic f a c t o r . The a r e a to be t r e a t e d may be f a r from any town or community and may be u n i n h a b i t e d except by the g r a z e r s whose l a n d use may be d i f f i c u l t t o change w i t h o u t an economic u p h e a v a l . (3) The V alue of Range Surveys i n D e t e r m i n i n g Range U t i l i z a t i o n  Few range management programs can be f u l l y e f f e c t i v e u n l e s s based on a t horough knowledge of the v e g e t a t i o n of t h e range u n i t under c o n s i d e r a t i o n . T h i s knowledge i n c l u d e s much more t h a n p r e s e n t g r a z i n g c a p a c i t i e s * i t i s i n t r i n s i c a l l y a knowledge of p r e s e n t v e g e t a t i o n c o n s i d e r e d i n terms of the most d e s i r a b l e v e g e t a t i o n t h a t might grow on the range u n i t i n v o l v e d (115). I t i s a l s o a knowledge of the s p e c i f i c l a n d use p r a c t i c e s t h a t have r e s u l t e d i n the p r e s e n t v e g e t a t i o n and of t h e r e m e d i a l measures t h a t w i l l restore d e t e r i o r a t e d a r e a s . I t i s , i n s h o r t , n e c e s s a r y t o r e c o g n i z e d i f f e r e n c e s i n range c o n d i t i o n and to d i f f e r e n t i a t e between top c o n d i t i o n and d e t e r i o r a t e d r a n g e s , to c l a s s i f y d i f f e r e n t degrees of d e t e r i o r a t i o n , and to p r e s c r i b e c o r r e c t i v e measures. Range surveys have as t h e i r o b j e c t i v e the f u r n i s h i n g of i n f o r m a t i o n n e c e s s a r y f o r sound range management of each a r e a s u r v e y e d . T h e i r p r i m a r y purpose i s to c o l l e c t d a t a which i n d i c a t e how much and what k i n d of use may be made of the range f o r a g e crop a n n u a l l y w i t h o u t i n j u r y to the f o r a g e , s o i l , or t o o t h e r n a t u r a l renewable r e s o u r c e s of r a n g e l a n d s . The s u r v ey s y s t e m a t i c a l l y n o t e s the amount of v e g e t a t i o n p r e s e n t - 57 -and i t s v a l u e t o g r a z i n g a n i m a l s . I t i s f u l l y concerned w i t h g a t h e r i n g a d d i t i o n a l f a c t s r e l a t i v e t o managing the range r e s o u r c e . Data from range su r v e y s o f f e r a dependable b a s i s f o r d r a f t i n g recommendations t o manage ranges such as crown g r a z -i n g l a n d s , l e a s e s , f o r e s t r e s e r v e s , o r ranges p r i v a t e l y owned. On ranges g r a z e d by an i n d i v i d u a l l y owned herd o f c a t t l e o r sheep, range s u r v e y s serve as a b a s i s f o r a f u t u r e management p o l i c y . The d a t a a p p l i e d t o maps a c t s as a guide t o numbers of s t o c k which may be p l a c e d on the l a n d , the c o r r e c t season and l e n g t h of g r a z i n g and the c o r r e c t l o c a t i o n of s a l t and w a t e r . Areas s u b j e c t t o e r o s i o n , p r e d a t o r s , r o d e n t s and poisonous p l a n t s can be c l e a r l y . m a r k e d and the n e c e s s a r y c o r -r e c t i v e s t e p s u n d e r t a k e n . The o b j e c t i v e s of t h e s e programs are t o improve the e x i s t i n g economic and s o c i a l c o n d i t i o n s which are d i r e c t l y c o r r e l a t e d w i t h the maintenance of these n a t u r a l renewable r e s o u r c e s . I n Western Canada, r a n g e l a n d s are h i g h l y i m p o r t a n t to the economy of Canada as w e l l as the commonwealth and as such problems connected w i t h management of the r a n g e l a n d s must be g i v e n s e r i o u s c o n s i d e r a t i o n . Range management p l a n s r e s u l t i n g f r o m a n a l y s i s and i n t e r -p r e t a t i o n o f range surveys must not approach t h e range problems s o l e l y from the r e s o u r c e management s t a n d p o i n g . E f f o r t must be made to harmonize th e e f f i c i e n t h a r v e s t of range f o r a g e w i t h the s o c i a l and economic w e l f a r e of t h e p o p u l a t i o n depending on the r a n g e l a n d r e s o u r c e s f o r a l i v i n g . - 58 -Range management and range s u r v e y i n g a r e , t h e r e f o r e , i n s t r u -ments d e s i g n e d to a s s i s t i n s o l v i n g the complex problems t h a t e v o l v e i n an attempt to m a i n t a i n l i v e s t o c k , f o r a g e , and the o t h e r n a t u r a l r e s o u r c e s produced on r a n g e l a n d s . Most c o n t r o v e r s y over the r e s u l t s of range su r v e y s c e n t e r s on t h e i r e s t i m a t e s of g r a z i n g c a p a c i t y , e s p e c i a l l y i f thes e e s t i m a t e s happen t o be c o n s i d e r a b l y l o w e r t h a n the numbers of a n i m a l s b e i n g g r a z e d on the range under c o n s i d e r a -t i o n . I n e v e r y c a s e , the survey s h o u l d be f o l l o w e d by an i n t e n s i v e , o b j e c t i v e range i n s p e c t i o n i n the f o l l o w i n g y e a r t o de c i d e whether the r e s u l t s o b t a i n e d a re sound. I f t h i s s t u d y i n d i c a t e s the g r a z i n g c a p a c i t y e s t i m a t e s made the p r e v i o u s y e a r are t o o l o w , t h e su r v e y s h o u l d not be d i s c r e d i t e d and i g n o r e d f o r t h e r e l a t i v e v a l u e s between the v a r i o u s s e c t i o n s o f the range may s t i l l be used and the whole c a r r y i n g c a p a c i t y e s t i m a t e may be r a i s e d or lo w e r e d as t h e s i t u a t i o n r e q u i r e s . A p a r t from f i n d i n g a c l u e t o g r a z i n g c a p a c i t y , the range manager f i n d s i n the range s u r v e y data a most s y s t e m a t i c and i m p e r s o n a l a p p r a i s a l of range v a l u e s , range problems and range c o n d i t i o n s . The i n i t i a t i o n of good range management t o date has been s e r i o u s l y handicapped t h r o u g h the l a c k of t h e s e fundamental s t u d i e s . The o b j e c t i v e s of range s u r v e y s and r e s e a r c h i n the range c o u n t r y of Canada and the U n i t e d S t a t e s a r e e s s e n t i a l l y s i m i -l a r . The p r a c t i c e s of range management b e s t adapted t o the c o n s e r v a t i o n of the l a n d and c o n s i s t e n t w i t h maximum u t i l i z a ^ t i o n , r e s t o r a t i o n , and maintenance of the f o r a g e s u p p l y and the most e f f e c t i v e p r o d u c t i o n of l i v e s t o c k are now w i d e l y a p p l i e d . They have been enumerated by W. R. C h a p l i n e as f o l l o w s : (a) D e f e r r e d and r o t a t i o n g r a z i n g (which p e r m i t s f u l l use of f o r a g e but d e l a y s g r a z i n g u n t i l a f t e r seed d i s s e m i n a t i o n ) on a d i f f e r e n t p o r t i o n o f the range each y e a r . (b) L a t e r opening d a t e s f o r r a n g e s , more i n harmony w i t h r e a d i n e s s of p l a n t s f o r g r a z i n g . ( c ) A f a i r l y good b a s i s f o r d e t e r m i n i n g t h e a p p r o x i -mate g r a z i n g c a p a c i t i e s of mountain range t y p e s . (d) Improved methods of g r a z i n g sheep and g o a t s , such as*, open and q u i e t h e r d i n g and bedding them down i n a new p l a c e e v e r y n i g h t t o a v o i d damaging the range t h r o u g h t r a m p l i n g and l o c a l i z e d o v e r g r a z i n g . (e) O b t a i n i n g the b e t t e r d i s t r i b u t i o n of c a t t l e on the range t h r o u g h w e l l p l a c e d w a t e r i n g f a c i l i -t i e s and b e t t e r s a l t i n g methods, thus b r i n g i n g about even and more e f f e c t i v e use of the a v a i l a b l e range f o r a g e . B. THE EFFECTS ON" INDIVIDUAL PLANTS While t h e u l t i m a t e u n i t of study i n g r a z i n g management i s the i n d i v i d u a l p l a n t , i t can h a r d l y be d i v o r c e d e n t i r e l y from the myriads of f a c t o r s which compose i t s environment o r , i n s h o r t , from t h e e c o l o g i c a l a s s o c i a t i o n . The p h y s i o l o g i s t i s a b l e to f o c u s h i s u n d i v i d e d a t t e n t i o n on the i n d i v i d u a l p l a n t , the range s p e c i a l i s t or range e c o l o g i s t , however, cannot be so s p e c i f i c . The p h y s i o l o g i s t may speak i n d e t a i l , of p l a n t f o o d r e s e r v e s i n the i n d i v i d u a l p l a n t , how they a c c u m u l a t e , how they are t r a n s l o c a t e d ; the range e c o l o g i s t , u n f o r t u n a t e l y , can o n l y i n t e r e s t h i m s e l f i n the f o o d r e s e r v e s as t h e y i n f l u e n c e - 6 0 ^ r e p r o d u c t i o n , f o r a g e p r o d u c t i o n , w i n t e r h a r d i n e s s , and r e -growth i n broad terms, and how range management of t h e a s s o c i a t i o n may be i n f l u e n c e d . G r a z i n g , r e g a r d l e s s of the season, has a marked e f f e c t on t h e m e t a b o l i c a c t i v i t y of a p l a n t . With the removal of f o l i a g e , p h o t o s y n t h e s i s i s reduced and hence t h e r e i s a r e d u c t i o n i n r o o t r e s e r v e s , r o o t p r o d u c t i o n , and f o r a g e p r o -d u c t i o n . Under moderate g r a z i n g , l e s s f o r a g e may be produced, but the i n c r e a s e i n q u a l i t y of f o r a g e w i l l compensate f o r t h i s r e d u c t i o n ( 2 1 4 ) • ( l ) E f f e c t on P l a n t Roots With o v e r g r a z i n g t h e r e i s , as p r e v i o u s l y mentioned, a r e d u c t i o n i n p h o t o s y n t h e s i s and hence a r e d u c t i o n i n growth of the e n t i r e p l a n t , both f o l i a g e and r o o t s . T h i s i s v e r y im-p o r t a n t under such c o n d i t i o n s s i n c e i t i s n e c e s s a r y f o r the p l a n t t o have ready a c c e s s t o s o i l n u t r i e n t s i n o r d e r t h a t the p h o t o s y n t h e t i c p a r t s of the p l a n t are w e l l s u p p l i e d w i t h these n u t r i e n t s n e c e s s a r y to r e p l a c e the g r a z e d f o l i a g e . Root development i s of f a r g r e a t e r i m p o r t a n c e i n s e m i - a r i d r e g i o n s such as r a n g e l a n d s than under c o n d i t i o n s of more abundant s o i l m o i s t u r e . T h e r e f o r e , under c o n d i t i o n s of m o i s t u r e s h o r t a g e , o v e r g r a z e d - p l a n t s s u f f e r more than n o r m a l l y or undergrazed p l a n t s . Under c o n d i t i o n s of o v e r g r a z i n g , wet s o i l s are compacted to a c o n s i d e r a b l e degree ( 1 3 9 ) . This makes them poor m o i s t u r e a b s o r b e r s and p r e v e n t s normal r o o t development. Hanson (102) i n s t u d y i n g t h e e f f e c t of o v e r g r a z i n g on awnless wheatgrass ( A g r o p y r o n inerme) found t h a t the r o o t s o n l y p e n e t r a t e d 44 cm., w h i l e on ungrazed a r e a s t h e y p e n e t r a t e d more than 65 cm. T h i s l a c k of adequate r o o t development impedes f o r a g e development d u r i n g p e r i o d s of m o i s t u r e s h o r t a g e ( 2 1 0 ) . (2) E f f e c t on P l a n t R e p r o d u c t i o n With o v e r g r a z i n g , not o n l y i s the r o o t development r e -duced, but the p l a n t r e p r o d u c t i o n i s a l s o i m p a i r e d . W h i l e i t i s not so i m p o r t a n t to have a h i g h r a t e of r e p r o d u c t i o n because of t h e l o n g e v i t y of the p e r e n n i a l p l a n t s c o m p r i s i n g the c l i m a x a s s o c i a t i o n s , i t i s i m p o r t a n t to have r e p l a c e m e n t s f o r those p l a n t s d e s t r o y e d by the g r a z i n g l i v e s t o c k . T h i s may i n t r o d u c e many problems f o r t h e range manager. These a n i m a l s may gra z e the p l a n t so h e a v i l y t h a t t h e y do n o t p e r m i t the development of a seed s t a l k . They may a l s o d i s r u p t the p h y s i o l o g y of the p l a n t to such a degree t h a t seed s e t t i n g i s i s not p e r m i t t e d . Hanson and S t o d d a r t (102) s t u d i e d the seed of awnless wheatgrass ( A g r o p y r o n inerme) on o v e r g r a z e d and p r o p e r l y g r a z e d r a n g e l a n d s . They found t h a t t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n the v i t a l i t y of the seed produced. However, when t h e s e two men c o n s i d e r e d the number or volume of seeds produced, t h e y found a s t r i k i n g d i f f e r e n c e . P r o p e r l y g r a z e d stands were found t o produce 50 ti m e s as many v i a b l e seeds as o v e r g r a z e d s t a n d s . Not a l l range s p e c i e s reproduce e x c l u s i v e l y by seeds. Many, e s p e c i a l l y i n the m o i s t e r a r e a s and g r a s s l a n d s a t - 61 -h i g h e r a l t i t u d e s , r eproduce by c r e e p i n g r o o t s t a l k s , r h i z o m e s , or s t o l o n s . However, the e f f e c t s of o v e r g r a z i n g are s i m i l a r t o t h o s e when p l a n t s reproduce s o l e l y by seed (103). I t i s t h e r e f o r e e s t a b l i s h e d t h a t o v e r g r a z i n g i s d e t r i -m e n tal t o both the development, r e p r o d u c t i o n and l o n g e v i t y of the p a l a t a b l e range p l a n t as an i n d i v i d u a l and i n a g r a z i n g a s s o c i a t i o n . What e f f e c t w i l l t h i s r e d u c t i o n have on the p e r -centage c o m p o s i t i o n of the c l i m a x a s s o c i a t i o n , i n c o m p e t i t i o n w i t h the u n p a l a t a b l e s p e c i e s of the a s s o c i a t i o n or i n v a d e r s such as m e c h a n i c a l l y i n j u r i o u s or p o i s o n o u s p l a n t s ? What e f f e c t w i l l t hese changes have on t h e c o n d i t i o n and numbers o f l i v e s t o c k g r a z i n g on such ranges? What e f f e c t w i l l t h e changes i n v e g e t a t i o n have on the s o i l i n such an a r e a ? These q u e s t i o n s can o n l y be answered a f t e r c a r e f u l s t u d y and keen o b s e r v a t i on. - 62 -I I I . THE EFFECTS OF OVERGRAZING ON DOMESTIC HERBIVORES On g r a s s l a n d ranges t h a t have been o v e r s t o c k e d t o such an e x t e n t t h a t o v e r g r a z i n g has r e s u l t e d , the a s s o c i a t i o n s o f p a l a t a b l e , p e r e n n i a l g r a s s e s and f o r b s g i v e way to a s s o c i a -t i o n s of low v a l u e , l e s s p a l a t a b l e g r a s s e s , f o r b s and b r u s h . The reasons f o r t h i s change have been d i s c u s s e d ( I I ) . The e f f e c t s of the s h o r t a g e of p a l a t a b l e s p e c i e s are f a r r e a c h i n g and of grave importance to the p r o d u c e r f o r many r e a s o n s , both d i r e c t and i n d i r e c t . These e f f e c t s a r e shown i n F i g u r e 6 and a r e d i s c u s s e d i n t h e f o l l o w i n g o r d e r : the i n f l u e n c e o f o v e r g r a z i n g on meat and wool p r o d u c t i o n , upon c a l f and lamb c r o p s , and upon death l o s s e s i n c l u d i n g those from p o i s o n o u s p l a n t s , s t a r v a t i o n , p r e d a t o r s and d i s e a s e . The h y p o t h e s i s t h a t t h e g r e a t e r the numbers of s t o c k per a r e a , the g r e a t e r t h e r e t u r n to the o p e r a t o r does not n e c e s s a r i l y a p p l y i n a l o n g - t e r m r a n g e l a n d g r a z i n g program and i n some cases i t does not a p p l y t h r o u g h o u t s h o r t - t e r m programs. The r e a s o n s f o r t h i s are d i s c u s s e d as w e l l as the l i m i t e d amounts of d a t a a v a i l a b l e p e r m i t . In. s t u d i e s such as t h e s e , the methods are c o m p l i c a t e d by the n e c e s s i t y of i n c l u d i n g such v a r i a b l e f a c t o r s as v e g e t a t i o n , topography and g e n e t i c make-up of the a n i m a l s . I t i s a l s o e x c e p t i o n a l l y d i f f i c u l t t o compare and a n a l y z e such f a c t o r s as T H E E F F E C T O F O V E R G R A Z I N G O N D O M E S T I C A T E D L I V E S T O C K P R O D U C T I O N -INCREASED YIELD OF POISONOUS a INJURIOUS PLANTS LOSSES FROM POISONOUS PLANTS -F i g u r e 12. The E f f e c t of L i v e s t o c k P r o d u c t i o n . O v e r g r a z i n g on Domesticated - 64 -v i g o r , d i s e a s e r e s i s t a n c e , and g r a z i n g e f f i c i e n c y i n the l i v e -s t o c k . T h e r e f o r e , due t o t h e c o m p l e x i t y of the methods n e c e s s a r y to a n a l y z e the l a r g e numbers of v a r i a b l e f a c t o r s which must be c o n s i d e r e d i n o r d e r t o t e s t the h y p o t h e s i s , many workers have i g n o r e d t h i s s e c t i o n of the r e s e a r c h work. While e f f e c t s of o v e r g r a z i n g on the v e g e t a t i o n and on the s o i l a r e f a i r l y w e l l known, the s t u d i e s c o n c e r n i n g the e f f e c t s on domesti c g r a z i n g a n i m a l s have h a r d l y begun. There i s a d e f i n i t e need f o r a great d e a l of work i n t h i s f i e l d i f the problems of meat p r o d u c t i o n and i t s i n t e r r e l a t i o n s h i p s are to be s o l v e d . A. INFLUENCE ON MEAT AND WOOL PRODUCTION The prime o b j e c t i v e of the r a n c h i n g i n d u s t r y i s the p r o -d u c t i o n of l a r g e amounts of h i g h q u a l i t y b e e f , mutton, lamb and w o o l . This p r o d u c t i o n s h o u l d be based on a l o n g - t e r m program, the v a l u e of the produce to be c o n s i d e r e d as a r u n -n i n g average over l o n g p e r i o d s of time r a t h e r t h a n on the p r o d u c t i o n of one or two y e a r s of i n t e n s i v e g r a z i n g . Very o f t e n stockmen are i n t e r e s t e d i n the a n i m a l s a l o n e and, i f the a n i m a l s are v i g o r o u s and t h r i f t y , t h e y b e l i e v e t h a t management i s adequate and o v e r g r a z i n g a b s e n t . Though such an i n d e x t o range c o n d i t i o n s appears s u p e r f i c i a l l y t o be sound, an inadequacy l i e s i n the f a c t t h a t a n i m a l s may appear t h r i f t y w i t h o u t making e c o n o m i c a l g a i n s . S t u d i e s have shown t h a t c a t t l e , though o c c a s i o n a l l y making some g a i n on t o o h e a v i l y used r a n g e s , do not g a i n - 65 -n e a r l y as much as on p r o p e r l y used ranges ( 8 8 ) . In s o u t h e r n Utah, on h e a v i l y g r a z e d range, a s t u d y of mixed c a t t l e showed t h a t g a i n s came i n the e a r l y season and t h a t l a t e r on some of t h e s e g a i n s were l o s t . T h i s was p r o b a b l y due t o the presence o f s h o r t - l i v e d a n n u a l s such as c h e a t g r a s s (Bromus  tect o r u m ) t h a t produced f o r a g e u n t i l t h e advent of hot weather when t h e y d r i e d up and/or s e t seed, becoming u n p a l a t a b l e or m e c h a n i c a l l y i n j u r i o u s . The average w e i g h t i n c r e a s e s over 1 the g r a z i n g season were 55 t o 90 pounds, depending on the age of t h e s t o c k . The gai n s were much l o w e r than s h o u l d be expe c t e d . Losses i n weight d i d not b e g i n i m m e d i a t e l y w i t h f u l l u t i l i z a t i o n o f the f o r a g e but o c c u r r e d some time a f t e r o v e r g r a z i n g had been r e a c h e d . S a r v i s (177) i n s t u d y i n g the r a t e of g a i n s under d i f f e r e n t i n t e n s i t i e s of g r a z i n g found t h a t c a t t l e made average g a i n s r a n g i n g from 294 pounds i n 7 0-acre p a s t u r e s down t o 180 pounds i n 3 0-acre p a s t u r e s . The q u a n t i t y of p a s t u r e removed was 51 p e r c e n t on 1 0 0-acre p a s t u r e s and 98 p e r c e n t on the 30-acr'e p a s t u r e s . The 2 p e r c e n t c a r r y - o v e r i s c o n s i d e r a b l y l o w e r t h a n the 45 p e r c e n t c a r r y - o v e r recommended' by the Dominion Department of A g r i c u l t u r e ( 4 6 ) . O v e r g r a z i n g r e s u l t s i n a reduced y i e l d of p a l a t a b l e , p e r e n n i a l g r a s s e s ( I I ) . T h i s p a l a t a b i l i t y . f a c t o r assumes s p e c i a l i m p o r t a n c e from t h e s t a n d p o i n t of f o r a g e s p e c i e s when s e l e c t i v e g r a z i n g over e x t e n s i v e a r e a s such as r a n g e l a n d i s p r a c t i s e d ( 1 5 ) . O b s e r v a t i o n s made by the a u t h o r on sheep range i n the Kamloops a r e a have shown t h a t sheep when p l a c e d - 66 -on new range choose c e r t a i n f a v o u r e d p a l a t a b l e s p e c i e s b e f o r e t h e y r e s o r t to normal s y s t e m a t i c g r a z i n g . When bands of sheep are p l a c e d on upper g r a s s l a n d ranges, i t i s not uncommon t o see them f a n o u t , c i r c l i n g the range at a f a s t walk or t r o t i n an attempt t o c r o p the w i l d p e a v i n e ( L a t h y r u s o r c h o l e u c u s Hook.) p r e s e n t i n the p l a n t a s s o c i a t i o n . At the same t i m e , much of t h e n u t r i t i o u s but l e s s p a l a t a b l e f o r a g e i s t r a m p l e d and r e n d e r e d u s e l e s s f o r l a t e r g r a z i n g . Now t h e s e o b s e r v a -t i o n s were not made on o v e r g r a z e d l a n d but the p r i n c i p l e a p p l i e s e q u a l l y w e l l and the s t o c k under such c o n d i t i o n s may e x c e s s i v e l y t r a m p l e many of t h e r e p r o d u c t i v e shoots and young p l a n t s w h i l e l o o k i n g f o r p a l a t a b l e s p e c i e s i n a s s o c i a t i o n s of low p a l a t a b i l i t y . T h i s movement has a marked e f f e c t on the meat p r o d u c i n g a b i l i t y of t h e l i v e s t o c k . W h i l e B u l l and Rusk (31) found t h a t e x e r c i s e has no e f f e c t on the toughness of beef and causes no s i g n i f i c a n t changes i n the f l a v o u r or o t h e r f a c t o r s of p a l a t a b i l i t y , t h e y d i d f i n d t h a t i t r e q u i r e d c o n s i d e r a b l y more n u t r i e n t s per 100 pounds g a i n . On overgrazed l a n d , t h e n , the s i t u a t i o n i s even more ac u t e s i n c e t h e g r a z i n g a n i m a l must g r a z e more f o r a g e per u n i t g a i n t h a n on an a r e a where the f o r a g e i s p l e n t i f u l . Doran (75) found t h a t under c o n d i -t i o n s c o n t r i b u t o r y t o o v e r g r a z i n g , sheep may l o s e about 2 hours f e e d i n g time a day and c o n s e q u e n t l y cause a g r e a t r e d u c t i o n i n the c o n d i t i o n of the lambs. I t a l s o causes e x c e s s i v e t r a v e l l i n g . Two o p i n i o n s e x i s t c o n c e r n i n g the f o r a g e consumption of - 67 -a n i m a l s on o v e r g r a z e d p a s t u r e . Raymond (167) found t h a t t h e amount eaten d a i l y was almost independent of the g r a z i n g a v a i l a b l e but i n c r e a s e d o n l y w i t h body s i z e . Johnstone-W a l l a c e (122) s t u d i e d t h e g r a z i n g b e h a v i o r of c a t t l e , f i n d i n g t h a t t h e y showed no i n c l i n a t i o n to extend the g r a z i n g p e r i o d per day beyond 8 hours, even when herbage consumed f e l l as low as 30 t o 45 p e r c e n t of t h e amount n o r m a l l y g r a z e d . In the f i r s t c a s e , i t i s b e l i e v e d t h a t t h e a n i m a l s w i l l t r a v e l f a r t h e r t o get the same amount of f o r a g e n u t r i e n t s but spend i n c r e a s e d amounts of energy i n o r d e r t o h a r v e s t the f e e d , t h e r e b y making a l o w e r r a t e of g a i n , i f any. In t h e o t h e r case, t h e a n i m a l s eat much l e s s and a l s o expend l e s s energy i n a t t e m p t i n g t o h a r v e s t a normal amount of f o r a g e . In both cases t h e net r e s u l t i s t h e same i n t h a t r e g a r d l e s s o f t h e a n i m a l ' s response t o the f e e d s h o r t a g e , t h e r a t e of g a i n w i l l be r e d u c e d . These f i n d i n g s a r e v e r i f i e d by White ( 2 5 6 ) . In summary, i t i s w e l l worth e m p h a s i z i n g t h a t range i n good c o n d i t i o n p r o v i d e s a w e l l b a l a n c e d d i e t . -Range i n poor con-d i t i o n i s d e f i c i e n t i n both q u a l i t y and amount of n u t r i e n t s . E x p e r i m e n t a t i o n conducted a t t h e Dominion Range E x p e r i -ment S t a t i o n , M a n y b e r r i e s , A l b e r t a ( 2 2 6 ) , showed t h a t g r a z i n g at t h e i n t e n s i v e r a t e of 20 a c r e s produced l e s s g a i n s per head than g r a z i n g a t 40 a c r e s per head. The p r o d u c t i o n of wool on o v e r g r a z e d l a n d i s a l s o s e r i o u s l y a f f e c t e d because of t h e r e d u c t i o n i n n u t r i e n t s a v a i l a b l e t o t h e g r a z i n g sheep. I t i s common knowledge t h a t t h e plane of n u t r i t i o n has a marked e f f e c t upon wool production. - 6.8 -M o r r i s o n (140) s t a t e s t h a t adverse c o n d i t i o n s such as s i c k -n e s s , undue exposure, or a d e c i d e d l a c k of f e e d w i l l d e c r e ase t h e y i e l d of wool and produce s m a l l e r f i b r e s . W i l s o n (258) found t h a t sheep on a f a t t e n i n g r a t i o n grew more wool, l o n g e r i n s t a p l e , s u p e r i o r i n c r i m p , and s t r o n g e r , t h a n sheep on a submaintenance r a t i o n such as may be f o u n d on h e a v i l y o v e r -g r a z e d r a n g e l a n d s . A l l e x p e r i m e n t a l e v i d e n c e ( 7 8 , 79 , 253) p o i n t s toward g r e a t e r wool p r o d u c t i o n when sheep are on a h i g h p l a n e of n u t r i t i o n , a f e a t u r e which emphasizes the need f o r p r o p e r g r a z i n g p r a c t i c e s which p e r m i t t h e r e p r o d u c t i o n of s u f f i c i e n t f o r a g e t o meet both t h e maintenance and p r o d u c t i o n needs of the a n i m a l . B. INFLUENCE ON CALF AND LAMB CROPS M a l n u t r i t i o n , r e g a r d l e s s of the cause, r e s u l t s i n p h y s i o -l o g i c a l d i s t u r b a n c e s , many of which under range c o n d i t i o n s escape n o t i c e . However, one p o i n t i s c l e a r r e g a r d l e s s of the cause or c a u s e s . Decreased lamb and c a l f c r o p s do not escape the n o t i c e of the producer and are o f grave concern t o him.. Friedman and Turner (86) found t h a t under e x i s t i n g d e f i c i e n -c i e s o f p r o t e i n , v i t a m i n A, and phosphorus have a marked e f f e c t on the l e v e l of r e p r o d u c t i o n . M i l l e r , Hart and C o l e ( 1 3 7 ) , however, i n s t u d y i n g f e r t i l i t y i n sheep, found t h a t a s e r i o u s d e p l e t i o n of v i t a m i n A r e s e r v e s was n e c e s s a r y b e f o r e o e s t r u s , o v u l a t i o n , b r e e d i n g , f e r t i l i z a t i o n and i m p l a n t a t i o n were a f f e c t e d . G e s t a t i o n , on the o t h e r hand, might become markedly a f f e c t e d w i t h t h e death of the f o e t u s i n u t e r o or - 69 -t h e b i r t h of weak lambs. When ranges have been o v e r g r a z e d , poor cows and ewes ar e not a b l e t o p r o v i d e nourishment f o r t h e i r young (83). The m o r t a l i t y r a t e of the o f f s p r i n g i s r e s u l t a n t l y v e r y h i g h a f t e r c a l v i n g or l a m b i n g . F r e q u e n t l y , cows w i t h young c a l v e s are i n such poor c o n d i t i o n i n t h e s p r i n g and e a r l y summer t h a t they do not l a t e r c o n c e i v e and c o n s e q u e n t l y c a l f o n l y i n a l t e r n a t e y e a r s . The r e s u l t i s e x t r e m e l y low c a l f c r o p s . C o n v e r s e l y , Baker and Queensbury (8) found t h a t when an i m a l s are g a i n i n g i n f l e s h due t o good p a s t u r a g e , a h i g h p e r c e n t a g e of c a l v e s and lambs i s i n v a r i a b l y produced. The p r a c t i c a l a p p l i c a t i o n of t h e s e f i n d i n g s has l o n g been used i n t h e p r o c e s s of f l u s h i n g ewes. Experiments conducted i n A r i z o n a (230) showed t h a t the c a l f c r o p on o v e r s t o c k e d ranges averaged o n l y 55 p e r c e n t i n c o n t r a s t w i t h an average of 72.6 p e r c e n t f o r the same p e r i o d on comparable but c o n s e r v a t i v e l y g r a z e d r a n g e s . S i n c e t h e h i g h e r the percentage c a l f c r o p , t h e l o w e r the c o s t per c a l f , i t i s f u r t h e r evidence t h a t o v e r g r a z i n g i n c r e a s e s the c o s t of r a n c h i n g o p e r a t i o n s . C. INFLUENCE ON DEATH LOSSES ( l ) P o i s onous P l a n t s With few e x c e p t i o n s , the poisonous p l a n t s of the range are not s p e c i e s abundant i n t h e c l i m a x a s s o c i a t i o n but d e v e l o p l a r g e numbers or a r e i n t r o d u c e d as a r e s u l t of heavy g r a z i n g . - 70 -With the e x c e p t i o n of h a b i t f o r m i n g s p e c i e s f o r which l i v e -s t o c k a c q u i r e a d e s i r e , poisonous p l a n t s a r e o n l y g r a z e d as a r e s u l t of hunger. The main cause of t h i s hunger i s poor range c o n d i t i o n s . The p r i n c i p a l poisonous p l a n t s (227) of the i n t e r i o r of B r i t i s h Columbia were found t o be t i m b e r m i l k v e t c h ( A s t r a -g a l u s s e r o t i n u s A. G r a y ) , l a r k s p u r ( D e l p h i n i u m s p p . ) , death camus (Zygodenus venerosus S. Watt.) and water hemlock ( C i c u t a o c c i d e n t a l i s Greene). The o r d e r of l i s t i n g i s approxi-m a t e l y t h a t pf r e l a t i v e i m p o r t a n c e . The f i r s t and l a s t poisonous p l a n t s l i s t e d are poisonous b o t h t o c a t t l e and t o sheep, l a r k s p u r ( D e l p h i n i u m spp.) m a i n l y t o c a t t l e , and death camus (Zygodenus v e n e r o s u s ) t o sheep. Because many r a n c h e r s omit t o r e p o r t the l o s s e s from poisonous p l a n t s , the e x a c t l i v e s t o c k l o s s e s from t h i s cause are not a v a i l a b l e f o r e i t h e r B r i t i s h Columbia or Canada, but r e p o r t s from o t h e r e x p e r i m e n t a l areas g i v e an i n d i c a t i o n . A comparison, however, between p r i v a t e l y owned ranges and p u b l i c domain i n A r i z o n a and New Mexico (151) has shown t h a t l o s s e s on m o d e r a t e l y g r a z e d , p r i v a t e l y owned ranges t o t a l l e d 8 . 7 p e r c e n t cows and 2.8 p e r c e n t o t h e r c a t t l e , w h i l e on the o v e r -g r a z e d p u b l i c domain 15 p e r c e n t cows and 3.5 p e r c e n t o t h e r c a t t l e were l o s t . When one c o n s i d e r s t h a t under good c o n d i -t i o n s 25 t o 27 p e r c e n t of t h e herd s h o u l d be marketed each y e a r , the 18.5 p e r c e n t l o s s s u f f e r e d on the p u b l i c domain c o n s t i t u t e s a t e r r i f i c economic r e d u c t i o n to the p r o d u c e r ' s income. S i m i l a r s i t u a t i o n s may be found t h r o u g h o u t the - 71 -w e s t e r n g r a z i n g a r e a s . F o r s l i n g (83) found t h a t the m o r t a l i t y from poisonous p l a n t s i s i n v a r i a b l y h e a v i e s t when l i v e s t o c k are hungry and/or when t h e range i s c l o s e l y g r a z e d . ^ i s o b s e r v a t i o n s a re supported by many o t h e r s (230, 214, 235, 212, 9 1 ) . Many poisonous p l a n t s are among the e a r l i e s t s p e c i e s t o make t h e i r appearance i n the s p r i n g ; and i f t h e s u p p l y of f o r a g e i s s h o r t , as i n the case o f . o v e r g r a z i n g , l i v e s t o c k a re a t t r a c t e d t o t h e s e p l a n t s t o a g r e a t e r degree than t h e y o t h e r -w i s e would be. S i n c e the s t o c k are i n a somewhat weakened c o n d i t i o n from the e f f e c t s of w i n t e r i n g and s h o r t f e e d , con-sumption of the s e poisonous p l a n t s causes i n c r e a s e d e m a c i a t i o n and death. As e x e m p l i f i e d by t i m b e r m i l k v e t c h ( A s t r a g a l u s  s e r o t i n u s ) . death i s not the. o n l y i l l e f f e c t of poisonous p l a n t s . V e ry o f t e n a f f e c t e d c a t t l e l o s e c o n d i t i o n and become s e v e r e l y emaciated. I n the advanced s t a g e s of p o i s o n i n g , t h e y w i l l s t a n d i n a s e m i - s t u p o r f o r l o n g p e r i o d s of t i m e , r e f u s i n g b o t h t o eat and to move. Of even g r e a t e r c o n c e r n t o the range manager i s the d i f f i c u l t y of h e r d i n g t h e s e a f f e c t e d a n i m a l s . I t i s t h e a u t h o r ' s b e l i e f t h a t a f f e c t e d wet cows c o n t i n u a l l y attempt t o l e a v e t h e s u b a l p i n e meadows and r e t u r n t o lo w e r l e v e l s where i t i s warmer d u r i n g the n i g h t and t h e t i m b e r m i l k v e t c h ( A s t r a g a l u s s e r o t i n u s ) grows because: ' ( l ) The a f f e c t e d c a t t l e f e e l the c o l d and dampness more than u n a f f e c t e d c a t t l e ; or (2) The a f f e c t e d c a t t l e become a d d i c t e d t o the t i m b e r m i l k v e t c h ( A s t r a g a l u s s e r o t i n u s ) poisonous p r i n c i p l e ; or (3) Both ( l ) and (2). - 72 -T h i s i n t r o d u c e s i n c r e a s e d r i d i n g and l a b o u r s i n c e the p o i s o n e d cows and t h e i r c a l v e s must be kept w i t h the herd where t h e y may be p r o t e c t e d from p r e d a t o r s , swamps, bogs, g u l l i e s , e t c . ( 2 ) S t a r v a t i o n and Other F a c t o r s . I n s t a n c e s of heavy death l o s s e s from s t a r v a t i o n ( 2 3 5 ) i n the southwest r e s u l t from misuse of the range and subsequent o v e r g r a z i n g . These l o s s e s o c c u r because ranges a r e s t o c k e d on t h e b a s i s of t h e f o r a g e produced d u r i n g good y e a r s w i t h l i t t l e or no p r e p a r a t i o n s f o r severe w i n t e r s or p e r i o d s of drought. G r i f f i t h s (91) s t a t e s t h a t the one f a c t o r which has c o n t r i -buted more than any o t h e r t o the d e p l e t i o n of the ranges i s the development of hay p r o d u c t i o n i n t h e range a r e a . As l o n g as stock were co m p e l l e d t o s u b s i s t t h e year round on t h e range, the l i m i t e d s u p p l y of w i n t e r f e e d r e n d e r e d i t impossible t o s u p p o r t enough s t o c k t o make s e r i o u s i n r o a d s on t h e more abundant summer growth. W h i l e h i s s t a t e m e n t s a r e t h e o r e t i -c a l l y c o r r e c t , i t i s d o u b t f u l i f t h e l i v e s t o c k c o u l d s u r v i v e a w i n t e r such as t h i s (1948-49) even i f t h e y had not be.en weakened or p o o r l y c o n d i t i o n e d f o r the w i n t e r by f e e d i n g on o v e r g r a z e d l a n d . In the a n n a l s of t h e l i v e s t o c k i n d u s t r y t h i s w i n t e r w i l l u n d o u b t e d l y be compared w i t h t h e s e v e r e w i n t e r s of t h e 1880's which f o r c e d r a n c h e r s t o p r e p a r e emergency f e e d on a l a r g e s c a l e . F o r s l i n g ( 8 3 ) found t h a t young a n i m a l s are s t u n t e d by the u n f a v o r a b l e c o n d i t i o n s and t h i s f u r t h e r r educes the income - 73 -from the l i v e s t o c k b u s i n e s s . In a r e a s such as i n t e r i o r B r i t i s h Columbia, under good g r a z i n g c o n d i t i o n s , s t o c k may be s o l d as g r o s s f a t t e n e d beef at an age known as l o n g y e a r -l i n g s or coming two (18-24 months of a g e ) . Under t h e s e con-d i t i o n s , t h e expense of w i n t e r i n g t h e a n i m a l s and g r a z i n g them f o r a n o t h e r year i s e l i m i n a t e d and much of t h e g r a s s l a n d f o r a g e may be d i v e r t e d to p r o d u c i n g more young s t o c k . When s t o c k are w i n t e r e d as l o n g y e a r l i n g s t h e y are h e l d on a maintenance'or submaintenance d i e t . Under such c o n d i t i o n s i t may t a k e a good p a r t of t h e s p r i n g and summer g r a z i n g seasons t o r e g a i n t h e weight l o s t d u r i n g t h e w i n t e r . T h i s f o r a g e and t h e hay used d u r i n g w i n t e r i n g i s e x p e n s i v e . Walker and L a n t o n (235) found t h a t the major causes of d eath among range l i v e s t o c k are poisonous p l a n t s , p r e d a t o r s and d i s e a s e , a l t h o u g h the importance of t h e s e v a r i e s g r e a t l y w i t h the k i n d of s t o c k and the r e g i o n c o n c e r n e d . Death l o s s e s are r e l a t e d t o range c o n d i t i o n s . As F i g u r e 12 i n d i -c a t e s , the poor or emaciated c o n d i t i o n of l i v e s t o c k f r e q u e n t l y c o n t r i b u t e s t o l o s s e w from o t h e r c a u s e s . O r d i n a r i l y , t h e number of c a l v e s k i l l e d by c o y o t e s i s s m a l l , but t h e s e l o s s e s i n c r e a s e when the dams are t o o weak t o p r o t e c t t h e i r young. This i s e s p e c i a l l y t r u e where the e maciated a n i m a l s and t h e i r c a l v e s have s t r a y e d from t h e r e s t of t h e h e r d (83). When c o y o t e s k i l l sheep on t h e range the p r o c e d u r e d i f f e r s somewhat. The a u t h o r has seen the f o l l o w i n g system used by t h e s e a n i m a l s w i t h g r e a t s u c c e s s . The c oyote does not a t t a c k the band of sheep d i r e c t l y but stampedes them a l o n g a - 74 - . r i d g e or t h e s i d e of a h i l l . As t h e sheep r u n , the weaker a n i m a l s are f o r c e d t o the s i d e s and back of t h e f l o c k . The c o yote moves i n on t h e d o w n h i l l s i d e of t h e f l o c k and as t h e sheep are r u n n i n g s e l e c t s h i s v i c t i m , grasps i t by t h e t h r o a t , and r o l l s d o w n h i l l w i t h i t . Death l o s s e s r e s u l t i n g from a l a c k of f o r a g e on o v e r g r a z e d i] range may m a n i f e s t themselves i n o t h e r j W a y s as w e l l . L o s ses c o n t i b u t e d t o f a c t o r s such as d i s e a s e a r e o f t e n i n d i r e c t l y the r e s u l t of o v e r g r a z i n g s i n c e s t o c k i n an emaciated or poor c o n d i t i o n are s u b j e c t t o d i s e a s e (256) and p a r a s i t e s b e a r i n g d i s e a s e s ( 2 3 0 ) . E m a c i a t i o n or poor c o n d i t i o n may r e s u l t i n death as a r e s u l t o f the i n a b i l i t y of t h e a n i m a l s t o overcome p h y s i c a l obstad.es such as bogs andjswamps or g u l l i e s i n t o which the a n i m a l s wander and then have not the s t r e n g t h t o s t r u g g l e back t o normal r a n g e l a n d . Almost a l l t h e s e f a c t o r s c o n t r i b u t i n g t o i n c r e a s e d death l o s s e s on the range can be t r a c e d d i r e c t l y or i n d i r e c t l y to o v e r g r a z i n g . These f a c t o r s c o n t r i b u t e d i r e c t l y t o economic l o s s e s s u f f e r e d by the p r o d u c e r . I t has been shown t h a t p r o p e r g r a z i n g has an i m p o r t a n t b e a r i n g on t h e many f a c t o r s c o n t r i b u t i n g t o the s u c c e s s of a r a n c h i n g e n t e r p r i s e . Through g r a z i n g management, h a r m f u l e f f e c t s of o v e r g r a z i n g on the l i v e s t o c k may be minimized, th e c a l f and lamb c r o p i n c r e a s e d , and more l i v e s t o c k produced and marketed at a h i g h e r p r o f i t . C ontinuous and dependable ranch income i s c o n t i n g e n t upon m a i n t a i n i n g t h e f o r a g e p r o -d u c t i o n at i t s maximum. Whereas an immediate maximum meat - 75 -y i e l d i s not always compatable w i t h range management, i t i s d e f i n i t e l y unwise f o r the range manager t o i g n o r e meat y i e l d s as an i n d e x t o c o r r e c t range use, f o r t h e p r o d u c t i o n of meat i s the g o a l of range management. S i n c e i t has no d i r e c t a p p l i c a t i o n t o human n u t r i t i o n , f o r a g e p r o d u c t i o n on the range i s not an end i n i t s e l f . - 76 -IV. THE EFFECTS OF OVERGRAZING ON THE SOIL The r e s u l t s o f o v e r g r a z i n g , as p r e v i o u s l y mentioned, do not end w i t h t h e r e d u c t i o n or removal of v e g e t a t i o n from the r a n g e l a n d . Rangeland, when i t i s i n the c l i m a x s t a g e or i s p r o p e r l y g r a z e d , i s i n b a l a n c e w i t h the e r o d i n g f o r c e s . At t h i s s t a g e , the s o i l has undergone a s e r i e s of developments from the o r i g i n a l r o c k or pa r e n t m a t e r i a l and has become a c l i m a x s o i l . Such a s o i l may be d e f i n e d as a s o i l which has ent e r e d a stage of r e l a t i v e s t a b i l i t y w i t h t h e c l i m a t e . Under th e s e c o n d i t i o n s , the downward movement of s o l u b l e m a t e r i a l s by l e a c h i n g i s b a l a n c e d by the upward movement of m a t e r i a l s by p l a n t s . G e o l o g i c a l e r o s i o n a s s i s t s the p l a n t s i n m a i n t a i n -i n g t h i s b a l a n c e . I n a c l i m a x s o i l t h e h o r i z o n t a l development i s complete and a c c e l e r a t e d e r o s i o n i s n e g l i g i b l e . F u r t h e r -more, a b i o l o g i c a l b a l a n c e i s a t t a i n e d i n which b a c t e r i a l and m u l t i c e l l u l a r a c t i v i t i e s are v i r t u a l l y c o n s t a n t , v a r y i n g o n l y w i t h t h e weather ( 1 4 8 ) . Now s i n c e v e g e t a t i o n i s the r e s u l t of t h e combined f a c t o r s of s o i l and c l i m a t e , i t f o l l o w s t h a t as a s o i l ap-proaches i t s c l i m a x , so a l s o does the v e g e t a t i o n . Under n o r m a l • c o n d i t i o n s , a c l i m a x s o i l s u p p o r t s a c l i m a x v e g e t a t i o n and both a r e i n a s t a t e of e q u i l i b r i u m w i t h the c l i m a t e . As t h e c l i m a t e v a r i e s , so does the v e g e t a t i o n , t h e an i m a l s l i v i n g on t h e v e g e t a t i o n and, t o a l e s s e r degree, the s o i l . A change - 77 -i n t h e p l a n t a s s o c i a t i o n , whatever the cause, i s almost c e r t a i n to a l t e r t h i s e q u i l i b r i u m . The change may be brought about by a l o n g p e r i o d of abnormal weather, a s e c u l a r change i n c l i m a t e , by a p a r a s i t e , f i r e , man, or a host of o t h e r causes ( 1 1 9 ) . With the i n t r o d u c t i o n of domestic g r a z i n g a n i m a l s , a new p l a n t a s s o c i a t i o n i s produced on w e s t e r n g r a z i n g l a n d s . T h i s change i n tte v e g e t a t i o n causes a r e d u c -t i o n i n s o i l f e r t i l i t y u n t i l e q u i l i b r i u m i s a g a i n e s t a b l i s h e d under t h e new v e g e t a t i v e c o n d i t i o n s . T h i s change has caused some a l a r m among b o t h s o i l and w i l d l i f e c o n s e r v a t i o n i s t s . The p r i m a r y problem of w e s t e r n r a n g e l a n d s , t h e n , i n v o l v e s d e v e l o p i n g a system of proper range u t i l i z a t i o n combined w i t h the p r e v e n t i o n of a c c e l e r a t e d s o i l e r o s i o n (7). T h i s f a c t i s borne out i n t h e r e s u l t s of i n v e s t i g a t i o n s (26l) of mismanaged and e x c e s s i v e l y o v e r s t o c k e d p a r t s of the P a l o u s e P r a i r i e . Young found t h a t changes i n the v e g e t a t i o n do not n e c e s s a r i l y i n d i c a t e t h a t pronounced changes have a l s o t a k e n p l a c e i n such c h e m i c a l c o n s t i t u e n t s of the s o i l as o r g a n i c m a t t e r , t o t a l n i t r o g e n , n i t r a t e - n i t r o g e n , and hydrogen i o n c o n c e n t r a t i o n u n l e s s e r o s i o n has been a s s o c i a t e d w i t h o v e r g r a z i n g . T h i s p a r t i c u l a r s t u d y (26l) has shown t h a t i n the P a l o u s e P r a i r i e r e g i o n , o v e r g r a z e d a r e a s which have not s u f f e r e d from e r o s i o n are not c h e m i c a l l y i m p o v e r i s h e d as h e r e t o f o r e assumed. Maximum p r o d u c t i o n on r a n g e l a n d i s always congruous w i t h maximum c o n s e r v a t i o n of s o i l and m o i s t u r e . V e g e t a t i v e c o n t r o l of e r o s i o n on the r a n g e l a n d t h e n c o n s i s t s of a c a r e f u l s t u d y of the l i v e s t o c k h a n d l i n g p r a c t i c e s and l i v e s t o c k numbers t o - 78 -determine any source of mismanagement t h a t g i v e s r i s e t o the d e t e r i o r a t i o n of the v e g e t a t i o n . A good c o v e r of v e g e t a t i o n i s t h e most d i r e c t and e f f e c t i v e means toward s o i l c o n s e r v a -t i o n . I t s h o u l d be e m p h a t i c a l l y r e p e a t e d t h a t under o v e r -g r a z e d c o n d i t i o n s the problem becomes t h a t of c o n t r o l l i n g s o i l e r o s i o n r e g a r d l e s s of whether i t i s caused by water or wind. On ranges where e r o s i o n i s p o t e n t i a l l y s e v e r e , s o i l s t a b i l i t y , not f o r a g e p r o d u c t i o n , s h o u l d be the measure of c o r r e c t use. A. WATER EROSION ('1) F a c t o r s I n f l u e n c i n g Water E r o s i o n W h i l e wind e r o s i o n i n a s e r i o u s form i s l a r g e l y c o n f i n e d t o r e g i o n s r e c e i v i n g below 15 i n c h e s of p r e c i p i t a t i o n per y e a r , such i s not the case w i t h water e r o s i o n . However, most of t h e areas s u b j e c t t o water e r o s i o n t h a t do r e c e i v e more annual p r e c i p i t a t i o n are engaged i n some form of a g r i -c u l t u r e o t h e r than r a n g e l a n d g r a z i n g and hence w i l l not be d i s c u s s e d . The q u e s t i o n may then be a s k e d : "How can the r u n - o f f from such a low a n n u a l p r e c i p i t a t i o n become a grave problem when a r e a s r e c e i v i n g c o n s i d e r a b l y more r a i n f a l l per year a r e v i r t u a l l y f r e e of h a r m f u l e r o s i o n ? " A g a i n , the c o n d i t i o n and type of v e g e t a t i o n found growing on the l a n d must be considered i n p r e s e n t i n g t h e answer t o such a q u e s t i o n . On more humid a r e a s , t h e v e g e t a t i o n o f t e n tends t o be sod-f o r m i n g i n n a t u r e . A good cover i s thus p r o v i d e d and t h e s o i l i s w e l l p r o t e c t e d by t h e w e l l - k n i t sod. On t h e a r e a s r e c e i v -i n g s m a l l amounts of p r e c i p i t a t i o n t h e v e g e t a t i o n tends to be - 79 -found i n bunches, p l a n t r e p r o d u c t i o n coming not from rhizomes and c r e e p i n g r o o t s t a l k s but from seed d i s t r i b u t i o n . Under c o n d i t i o n s of c l i m a x or p r o p e r g r a z i n g u t i l i z a t i o n , t h e s e p l a n t s are a b l e t o w i t h s t a n d t h e e r o s i v e f o r c e s of the p r e -c i p i t a t i o n . T h e r e f o r e i f water e r o s i o n i s to be c u r t a i l e d and c o n t r o l l e d t h e v e g e t a t i o n must be k e p t i n a c o n d i t i o n t h a t w i l l p e r m i t i t t o f u l f i l l the demands of s o i l c o n s e r v a -t i o n as w e l l as t h e r e q u i r e m e n t s of the s t o c k g r a z i n g t h e r e o n . When o v e r g r a z i n g i s p e r m i t t e d , t h e s e v e g e t a t i v e c o n t r o l s a r e reduced, r e s u l t i n g i n water e r o s i o n . S i p e or topography i s a v i t a l f a c t o r i n f l u e n c i n g the degree or r a t e of e r o s i o n . As the s l o p e s t e e p e n s , not o n l y does the v e l o c i t y of the r u n - o f f w a t e r i n c r e a s e , but t h i s e r o s i o n f a c t o r i s a l s o a s s i s t e d by g r a v i t y . The v e l o c i t y of r a i n f a l l i s of i m p o r t a n c e i n d e t e r m i n i n g the r a t e and amount of s u r f a c e f u n - o f f and hence the p o t e n t i a l e r o d i n g c a p a c i t y of such r u n - o f f . The n a t u r e and t e x t u r e of the s o i l i s a l s o of impar tance s i n c e d i f f e r e n t t e x t u r e d s o i l s e x h i b i t d i f f e r -ent s u s c e p t i b i l i t i e s t o e r o s i o n . I t i s o b v i o u s , t h e r e f o r e , t h a t s i n c e the a l t e r a t i o n of range topography, s o i l , and p r e c i p i t a t i o n v e l o c i t y i s e i t h e r e x p e n s i v e or i m p o s s i b l e , t h e o n l y f e a s i b l e method of c o n t r o l l i n g w ater e r o s i o n i s t h r o u g h the proper management of the r a n g e l a n d v e g e t a t i o n ( 7 ) . (a) Role of the Gross Morphology of the V e g e t a t i o n i n S o i l P r o t e c t i o n  I t has been p o i n t e d o u t t h a t i n an e s t a b l i s h e d eco-system t h e e f f e c t s of e r o s i o n are o f f s e t by the a c t i v i t i e s of F i g u r e 14. Research e n c l o s u r e A I I I . Note the l o w e r and upper g r a s s l a n d r e g i o n s i n the background. - 81 -the p l a n t a s s o c i a t i o n s c o m p r i s i n g the c l i m a x v e g e t a t i o n . I f t h e e x c l u s i o n of g r a z i n g i s p e r m i t t e d , t a l l stemmy herbage becomes dominant (119), the s o i l p r o t e c t i n g bottom g r a s s e s and f o r b s are choked out w i t h t h e r e s u l t t h a t a g a i n t h e r e i s an i n c r e a s e of bare ground. An example of t h i s may be shown i n F i g u r e s 13 and 14. T h i s e n c l o s u r e , named A I I I , was e s t a b l i s h e d on M a r a Mountain near Kamloops and a l l g r a z i n g was e x c l u d e d . I n d i c a t i o n s of r e p r o d u c t i o n are n e g l i g i b l e and l a r g e bare spaces between t h e p l a n t s g i v e ample e v i d e n c e t h a t the w a t e r r e q u i r e m e n t s of t h e s e p l a n t s p r e v e n t s the more u n i f o r m type of cover found on n o r m a l l y u t i l i z e d a r e a s . There i s a l s o a tendency toward e x c e s s i v e d r y i n g o f the t o p s o i l between t h e p l a n t s d u r i n g the summer drought p e r i o d , l e a v i n g the s o i l q u i t e s u s c e p t i b l e t o e r o s i o n . I t i s t h e r e f o r e e v i -dent t h a t oomplete p r o t e c t i o n i s a d e t r i m e n t t o the l a n d , b oth to the s o i l as such and e c o n o m i c a l l y i n t h a t n e i t h e r game nor commercial meat i s b e i n g produced. (b) I n f l u e n c e of the V e g e t a t i o n on the S o i l M i c r o e l e m e n t s ;  The s o i l s u r f a c e under a p l a n t c o v e r may seldom i f ever r e c e i v e t h e d i r e c t r a y s of the sun, and t h i s markedly reduces e v a p o r a t i o n . A f u r t h e r r e d u c t i o n of e v a p o r a t i o n i s n o t e d s i n c e the p l a n t a s s o c i a t i o n a c t s as a windbreak, l e a v i n g a b l a n k e t of humid a i r i m m e d i a t e l y over the s o i l s u r f a c e . Reduced sunshine and reduced h u m i d i t y l o w e r e v a p o r a t i o n from the s o i l s u r f a c e and p r e v e n t the s o i l from d r y i n g . S i n c e t h e p l a n t s draw s u b s o i l m o i s t u r e f o r t r a n s p i r a t i o n (214), the F i g u r e 15. E x c l o s u r e on N i c o l a Range showing R e s u l t s of Four Year's P r o t e c t i o n from G r a z i n g . v e g e t a t i o n may be s a i d t o make the s o i l w a ter more e v e n l y d i s t r i b u t e d , d r y i n g the s u b s o i l and keeping the s u r f a c e s o i l m o i s t e r . This i s an i d e a l c o n d i t i o n f o r a b s o r p t i o n i n the s u r f a c e s o i l , m o i s t s o i l a b s o r b i n g water more r e a d i l y t h a n d r y s o i l . The i n f l u e n c e of the v e g e t a t i o n on t h e s o i l m i c r o -f l o r a p r e v e n t s e x c e s s i v e d r y i n g of heavy s o i l s and the f r e e z i n g and thawing of o t h e r s o i l s which have been exposed t o the d i r e c t a c t i o n of the sun and wind causes c r a c k i n g or • heaving owing t o the absence or presence of m o i s t u r e i n abnormal amounts i n t h e s o i l . T h is c r a c k i n g or b e a v i n g of the s o i l which c o n t r i b u t e s t o e r o s i o n may a l s o break p l a n t r o o t s or a c t u a l l y d e s t r o y them by p u s h i n g them out of the s o i l . - 83 -G r a s s l a n d a s s o c i a t i o n s a r e of g r e a t importance i n p r o -t e c t i n g the s o i l from the e r o d i n g e f f e c t s o f r a i n f a l l . By-i n t e r c e p t i n g the r a i n f a l l , t h e v e g e t a t i v e canopy may h o l d the m o i s t u r e u n t i l such time as i t can be e v a p o r a t e d . I n t h i s way, some of t h e m o i s t u r e never r e a c h e s the ground and hence e r o s i o n i s i m p o s s i b l e (13). Another e f f e c t of the v e g e t a t i v e cover i s t h a t when the r a i n f a l l s t r i k e s the v e g e t a t i v e canopy the impact of the m o i s t u r e on t h e s o i l i s reduced to a con-s i d e r a b l e degree. In some cases a p e r i o d of one t o two hours may e l a p s e w h i l e the m o i s t u r e runs from the p o i n t of i n t e r -c e p t i o n on the f o l i a g e to the ground. I n g e n e r a l , v e r y l i t t l e a t t e n t i o n has been g i v e n to the amount of m o i s t u r e h e l d by the v e g e t a t i o n , w h i l e g r e a t p u b l i c i t y i s g r a n t e d m o i s t u r e e v a p o r a -t i o n f r om the s o i l and t r a n s p i r a t i o n from the p l a n t s . - The amount of m o i s t u r e h e l d depends upon a number of f a c t o r s , such as the k i n d and d e n s i t y of the p l a n t c o v e r , the d u r a t i o n and i n t e n s i t y of the r a i n f a l l , and the t e m p e r a t u r e , r e l a t i v e h u m i d i t y and wind movement. When the amount of m o i s t u r e i s e x p r e s s e d i n tons p e r a c r e , the magnitude of i n t e r c e p t i o n by herbaceous v e g e t a t i o n may be more r e a d i l y a p p r e c i a t e d . ' Sweet c o v e r , i t has been n o t e d , i s c a p a b l e o f h o l d i n g 8.0 t o n s , w h i l e p r a i r i e sage ( A r t e m i s i a g n o o h o l o d i e s N u t t . ) , under com-p a r a b l e c o n d i t i o n s , r e t a i n e d 12.5 t o n s per a c r e (44) • S i n c e o v e r g r a z i n g l e a d s to a d e t e r i o r a t i o n i n b o t a n i c a l c o m p o s i t i o n and an i n c r e a s e i n stemray a n n u a l g r a s s e s and weeds, as w e l l as to an i n c r e a s e i n bare ground, f u r t h e r w e i g h t i s added to the argument t h a t e r o s i o n c o n t r o l and s o i l conservation - 84 -on g r a s s l a n d s of a l l t y p e s are synonymous w i t h good range management. U n i t e d S t a t e s Department of A g r i c u l t u r e F o r e s t S e r v i c e t e s t s (60) on Ida h o . r a n g e l a n d s which a re s i m i l a r t o thos e of the s o u t h e r n i n t e r i o r of B r i t i s h Columbia were made on f o u r t y p e s of v e g e t a t i o n u s i n g a r t i f i c i a l r a i n machines. The f o u r types i n c l u d e d (a) awnless wheatgrass ( A g r o p y r o n i n e r m e ) , r e p r e s e n t a t i v e of the g r a s s l a n d c l i m a x ; (b) l u p i n e s and needle g r a s s ( L u p i n u s spp. and S t i p a l i t t e r m a n i i ) , p e r e n n i a l s r e p r e s e n t i n g the e a r l y stage of d e p l e t i o n f r o m g r a z i n g ; (c) annual g r a s s (Bromus t e c t o r u m ) , a l a t e r stage of g r a z i n g d e p l e t i o n ; and (d) annual weeds (Gayophylum. madia and Lac-t u c a ) , an i n f e r i o r range cover brought about by i n t e n s e misuse. Average o b s e r v a t i o n s f o r each type ( v e g e t a t i o n a l ) , a l l o t h e r ' f a c t o r s h a v i n g been i s o l a t e d , are shown i n Table IV. TABLE IV Run-off and E r o s i o n f r o m Four V e g e t a t i o n Types of Southern Idaho (44). WHEAT- LUPINE & ANNUAL ANNUAL VEGETATION TYPE GRASS NEEDLE GRASSES WEEDS (a) GRASS (c ) (d) (b) Run-off ( p e r c e n t ) 0.4 49.9 25.5 60.8 S o i l eroded (tons/A) 0.003 2.38 1.05 7-64 F u r t h e r evidence of t h e e r o s i o n c o n t r o l of each p l a n t a s s o c i a t i o n i n shown i n C a l i f o r n i a e x p e r i m e n t s which demon-s t r a t e d t h a t a s o i l c o v e r of sagebrush ( A r t i m e s i a t r i d e n t a t a ) and g r a s s s u p p l i e d a r e l i a b l e source of f o r a g e and a s t a b l e - 85 -y e a r - r o u n d p r o t e c t i o n f o r t h e s o i l (161). When t h i s l a n d i s c u l t i v a t e d and p e r m i t t e d to produce u n r e l i a b l e weedy c o v e r s such as R u s s i a n t h i s t l e ( S a l s o l a p e s t i f e r ) and mustards ( B r a s s i c a and Sisymbrium s p p . ) , e r o s i o n i s a sure r e s u l t . ( c ) Chemical and P h y s i c a l A c t i v i t i e s of the V e g e t a t i o n i n S o i l P r o t e c t i o n  The decayed m a t t e r or " d u f f " t h a t c o v e r s t h e s o i l under v e g e t a t i o n t h a t i s a l l o w e d a c a r r y - o v e r or i s l e f t un-g r a z e d i s an i m p o r t a n t p r o t e c t i o n a g a i n s t e r o d i n g agents and an a i d i n a b s o r b i n g water. E x p e r i m e n t s (81) have shown t h a t the l i t t e r f r o m one square metre- of g r a s s l a n d has absorbed as much as 650 gms. of water. However, the p r o t e c t i v e a c t i v i t i e s o f the p l a n t do not end w i t h " d u f f " . One of the b e n e f i t s d e r i v e d from p l a n t r o o t s i s the t r a n s f e r of o r g a n i c m a t t e r to the s u b s o i l . Over a p e r i o d of time an o r g a n i c r e s e r v e i s b u i l t up i n the s u b s o i l w hich r e s u l t s i n a h i g h e r water h o l d i n g c a p a c i t y and i n c r e a s e d p e r m e a b i l i t y because of improved s t r u c t u r e . S t u d i e s conducted i n Nebraska by Weaver et a l (249) showed t h a t under p r a i r i e g r a s s e s the pore space i n the s o i l d e c r e a s e s from 60 p e r c e n t of the volume a t 6 i n c h e s to 51 p e r c e n t at 7 f e e t . P r a i r i e .plants are l a r g e l y g r a s s e s and t h e p a r t s underground c o n s i s t of r o o t s , rhizomes and bases of stems. As a r e s u l t of the i n t e r l a c i n g and c l u t c h i n g of the p a r t i c l e s of e a r t h by the myriads of r o o t s of g r a s s e s , t h e s o i l i s compressed i n t o g r a n u l e s and t h e s e are surrounded by c o l l o i d a l f i l m s which m a i n t a i n t h e i r permanence and s t a b i l i t y . The l i v i n g under-- 86 -ground p a r t s i n t h e p r a i r i e compose a p p r o x i m a t e l y o n e - t e n t h of the t o t a l o r g a n i c m a t t e r by w e i g h t . These p l a n t p a r t s s l o w l y d e t e r i o r a t e , d i e and decay w i t h the p a s s i n g of y e a r s , o n l y t o be r e p l a c e d by new ones (239)• The c h a n n e l s which were made by the r o o t s i n p r e s s i n g a s i d e t h e s o i l remain f o r a l o n g p e r i o d of t i m e , g r e a t l y i n c r e a s i n g the pore space and conse-q u e n t l y the a b s o r p t i o n of water (23l). The c l o s e dependence of t h i s o r g a n i c m a t e r i a l upon the abundance and v i g o r of the t o p s cannot be overemphasized. Frequent removal of the to p s may cause them to d i e or t h e amount of o r g a n i c m a t t e r i n the s o i l t o be c o n s i d e r a b l y r e d u c e d . W i t h o v e r g r a z i n g t h e r e i s a l s o a r e d u c t i o n i n the p l a n t r o o t r e s e r v e s as w e l l as a dec r e a s e i n r o o t volume which i n t u r n reduces the degree of g r a n u l a t i o n and p o r o s i t y p r e s e n t . F l o r y (8l) s t a t e s t h a t s o i l s t r u c t u r e i s m a t e r i a l l y a l t e r e d by b o t h c u l t i v a t i o n and g r a z i n g . He found t h a t 6 y e a r s of c u l t i v a t i o n reduced the pore space of a c l i m a x p r a i r i e s o i l f rom 50.5 t o 44.3 p e r c e n t and the r a t e of p e n e t r a t i o n of water from 0.94 to 0.54 i n c h e s per hour. I n s t u d y i n g u n d e r g r a z e d , o v e r g r a z e d and d e p l e t e d ranges i n New Mexico, he found a pore space of 68.1, 51.1 a n d 46.5 p e r c e n t r e s p e c t i v e l y . The i n c h e s of water p e r n e t r a t i o n p e r hour were 4«14, 2.16, and 0.28 r e s p e c t i v e l y . T his d a t a i s shown i n Table V. - 87 -TABLE V Decrease i n Pore Space and Water P e n e t r a t i n g Rate i n Undergrazed, Overgrazed, and D e p l e t e d New Mexico Ranges (81)  UNDERGRAZED OVERGRAZED DEPLETED RANGE RANGE RANGE Pore space {%) 6 8 . 1 51.1 46.5 Water P e n e t r a t i o n Rate ( i n / h r ) 4.14 2 .16 0.82 (d) M e c h a n i c a l A c t i v i t i e s of t h e V e g e t a t i o n i n S o i l P r o t e c t i o n  P l a n t r o o t s , i n s p i t e o f t h e i r apparent t e n d e r n e s s and f r a i l t y , a r e able t o e x e r t p r e s s u r e s w e l l over 100 pounds per square i n c h by os m o t i c p r e s s u r e a l o n e . T h i s f o r c e e n a b l e s the r o o t s to open h o l e s and c r a c k s w h i c h p e r m i t the p e r c o l a -t i o n of water t h r o u g h the s o i l . T h i s same p r e s s u r e a l s o a s s i s t s i n p r e v e n t i n g e r o s i o n by moulding the s o i l p a r t i c l e s i n t o g r a n u l e s , thus i m p r o v i n g the s o i l s t r u c t u r e . Grass swards i n p a r t i c u l a r and o t h e r v e g e t a t i o n a l a s s o c i -a t i o n s i n g e n e r a l o b s t r u c t the f l o w of r u n - o f f w a t e r , t h e r e b y r e d u c i n g i t s r a t e of f l o w . The r e d u c t i o n i n the r a t e of f l o w to o n e - h a l f i t s o r i g i n a l speed w i l l reduce the e r o d i n g power of the water to o n e - f o u r t h and the amount o f m a t e r i a l i t can c a r r y t o one t h i r t y - s e c o n d ( 6 ) . The r e d u c t i o n i n v e l o c i t y i s a t t r i b u t a b l e p a r t l y t o the v e g e t a t i o n h o l d i n g some of the water back, p a r t l y because i t spreads the water out over a g r e a t e r a r e a of s o i l s u r f a c e , t h e r e b y r e d u c i n g i t s volume and i n c r e a s i n g the d i s t a n c e i t must f l o w , and p a r t l y because debris such as s t i c k s , dead l e a v e s and stems lodge between the p l a n t s . E F F E C T O F O V E R G R A Z I N G A N D E R O S I O N O N W E S T E R N G R A Z I N G R E G I O N S 8 I T S R A M I F I C A T I O N S OVERGRAZING LOSS OF VEGETATIVE . COVER DIMINISHED UNDER-GROUND WATER SUPPLY DROUGHT (INTENSIFIED PERIODS) PARASITES,^  DISEASE INCREASED NUMBERS OF INSECTSSMALL MAMMALS, PREDATORY ANIMALS ETC. EROSION INCREASED SPEED OFF RUN-OF' REDUCED LIVE— . STOCK PRODUCTIO DESTRUCTION OF FOOD 8 COVER FOR WLDLIFE a FISH DEPOSITION OF POOR SUBSOIL MATERIAL ON RICH ALLUVIAL SOILS IMPOVERISHMENT DUSTSTORMS- LOSS OF TOPSCHL a NUTRIENTS REDUCED YEILDS DETERIORATION OF SOIL FERTILITY SUFFERING DISEASE DEATH - FLOODS- DAMAGE TO ROADS •RAILROADS FARM BUILDINGS ETC-SEDIMENTATION IN NAVIGATION CHANNELS RESERVOIRS DAMS AND DtTCHES HARBOURS LOSSES IN NAVIGATION CITY WATER SUPPLY HYDROELECTRIC POWER '. IRRIGATION DEVELOPMENT FARMING & GRAZING F i g u r e 16. - 8? -(2) R e s u l t s of Water E r o s i o n The r e s u l t s of s e r i o u s water e r o s i o n combined w i t h t h e e f f e c t s of wind e r o s i o n , o r by i t s e l f , p r e s e n t a p i c t u r e o f d e s t r u c t i o n and d e s o l a t i o n the e q u a l of which would be exceed-i n t l y d i f f i c u l t t o f i n d . Throughout the e a r l y l i t e r a t u r e o f t h i s c o n t i n e n t t h e r e were c o u n t l e s s warnings t h a t e r o s i o n would s u r e l y r e s u l t from the systems of g r a z i n g p r a c t i s e d . Many of the p u b l i c a t i o n s ( 8 9 , 108, 127) were w r i t t e n p r i o r t o the t u r n of the Century. U n f o r t u n a t e l y , u n t i l t he mid-t h i r t i e s any mention of the d e s i c c a t i o n o f the Canadian West (or of the we s t e r n U n i t e d S t a t e s ) almost i n v a r i a b l y produced a c o u n t e r b l a s t of p r o t e s t t h a t t h e r e i s s t i l l ample good l a n d f o r a l l and t h a t the p i o n e e r i n g s p i r i t s t i l l l i v e s i n the p r o p l e s t r o n g enough to overcome a l l d i f f i c u l t i e s . The p e r -s i s t e n c e of o p i n i o n s such as t h i s r e s u l t e d i n the n e c e s s i t y of i n t r o d u c i n g the P r a i r i e Farm R e h a b i l i t a t i o n A c t (1935) by which p r o v i s i o n i s made t o remedy the consequences o f o v e r -g r a z i n g , drought and s o i l d r i f t i n g i n w e s t e r n Canada. I t i s i n t e r e s t i n g t o note t h a t the money i s used not o n l y f o r d i r e c t a s s i s t a n c e and r e s e a r c h but a l s o f o r propaganda and e d u c a t i o n ' a move toward e l i m i n a t i n g a l l the c o n t r i b u t a r y causes of poor l a n d u t i l i z a t i o n . U n f o r t u n a t e l y the c o n d i t i o n s brought about by water e r o s i o n are not r e a d i l y r e c t i f i e d . Dr. W. R. C a h p l i e has s t a t e d (4l) t h a t s i n c e the West i s dependent on g r a z i n g of the range f o r the e x i s t e n c e of i t s l i v e s t o c k i n d u s t r y i t i s i m p e r a t i v e t h a t the t e r r i f i c wastage - 90 -e x e m p l i f i e d by 80 percent abnormal e r o s i o n of western range-lands be h a l t e d . The most v a l u a h l e e r o s i o n c o n t r o l a v a i l -a b l e , a n a t u r a l p l a n t cover, must be developed i n order to decrease m a t e r i a l l y the l o s s e s o f t e n measured i n tons per a c r e . Such e s t i m a t i o n s of e x c e s s i v e s o i l l o s s are not n e c e s s a r i l y a l a r m i s t s ' dreams. The l i t e r a t u r e c o n t a i n s a wealth of experimental evidence to v e r i f y such a statement. P i c k f o r d and ReM (160), while studying subalpine g r a s s l a n d ranges of eastern Oregon and Washington, found t h a t the heavy g r a z i n g of these areas induced by the high q u a l i t y of the summer forage they produce and by the n a t u r a l . s h o r t a g e of summer range i n the r e g i o n has reduced t h e i r g r a z i n g c a p a c i t y f a r below the p o t e n t i a l . T h e i r study, which was made i n the Wallawa and Blue Mountains i n d i c a t e s that 927 tons of t o p s o i l per acre and 96 percent of the g r a z i n g c a p a c i t y was l o s t when th a t range was s e v e r e l y d e p l e t e d . The studyshows t h a t the green fescue type, which i s the most pr e v a l e n t p l a n t a s s o c i a t i o n i n the subalpine zones i n the northwest, c o n s i s t s of n e a r l y pure stands, of fescue when i n the v i r g i n , o o n d i t i o n but t h a t needle grass and r u d e r a l weeds predominate when t h i s type has become d e t e r i o r a t e d . Subalpine ranges i n a climax c o n d i t i o n possessed a g r a z i n g c a p a c i t y of 5»35 sheep months per a c r e . In a depleted second weed stage when, as p r e v i o u s l y mentioned, the v e g e t a t i o n was c h i e f l y needle grass and weeds, the g r a z i n g c a p a c i t y was but 0 .21 sheep months per a c r e . Now u n f o r t u n a t e l y the e f f e c t s of o v e r g r a z i n g do not end with the l o s s of v e g e t a t i o n and t o p s o i l . T h i s s o i l which was - 9 1 -such an a s s e t t o the r a n g e l a n d and the p l a n t s t h e r e o n becomes an expense and a menace as i t i s washed down t o l o w e r r e g i o n s . As i n d i c a t e d i n F i g u r e 16, t h i s s o i l may appear as sediment i n stream c h a n n e l s , r e s e r v o i r s , dams, d i t c h e s and har b o u r s . The g r a v i t y of the economic and s o c i a l i m p l i c a t i o n s brought about i n t h i s manner may be i l l u s t r a t e d by the f o l l o w i n g examples. The Morena d r a i n a g e b a s i n i s an im p o r t a n t d r a i n a g e b a s i n f o r w a ter g a t h e r i n g f o r t h e c i t y of San Diego, C a l i f o r n i a , and i s the s i t e of a dam and r e s e r v o i r completed i n 1910. I t was found t h a t by 1935, 10.5 p e r c e n t o f the r e s e r v o i r s t o r a g e c a p a c i t y had been d i s p l a c e d by se d i m e n t a r y deposits ( l l ) . That was over a p e r i o d of o n l y 25 y e a r s . C a t t l e g r a z i n g has been m a i n t a i n e d as the p r i n c i p a l l a n d use i n the a r e a . O v e r g r a z i n g the v a l l e y s and r e p e a t e d b u r n i n g of the brushy s l o p e s f o r the p r o d u c t i o n of s p r o u t s and weed f o r a g e have been the c h i e f cause of a c c e l e r a t e d e r o s i o n . Mr. W. T a l b o t has r e p o r t e d (218) t h a t s o u t h w e s t e r n s t o c k 1 w a t e r i n g r e s e r v o i r s s i l t a t an average r a t e of one f o o t p e r y e a r . At t h i s rage he c o n s i d e r s t h a t most of the r e s e r v c i r s w i l l be u s e l e s s i n 15 y e a r s or l e s s . D u r i n g the p e r i o d 1935-36 t o 1943-44, the P.F.R.A. spent a p p r o x i m a t e l y #450,000.00 on s t o c k w a t e r i n g dams alone (38). I f t h i s d a t a i s a p p l i c -a b l e t o the Canadian West, i t w i l l c o s t the P.F.R.A. $30,000.00 a year to m a i n t a i n t h e p r e s e n t s t o c k w a t e r i n g f a c i l i t i e s alone. The r a m i f i c a t i o n s of the r e s u l t s of s e d i m e n t a t i o n may be r e a d i l y seen i n a r e d u c t i o n i n f a r m i n g and range u t i l i z a t i o n - 9 2 -because of a l a c k of i r r i g a t i o n and s t o c k w a t e r i n g s u p p l i e s , and a r e d u c t i o n of s h i p p i n g i n r i v e r e s t u a r i e s because of the expense of r e p e a t e d d r e d g i n g i n an attempt t o keep the s h i p -p i n g c h a n n e l open t o n a v i g a t i o n . W h i l e e v e r y p o i n t mentioned i n F i g u r e 16 i s of g r e a t importance u n d o u b t e d l y one of the most i m p o r t a n t i s the f l o o d s which r e s u l t from o v e r g r a z i n g . I f t he prop e r u t i l i z a t i o n o f r a n g e l a n d s was undertaken i m m e d i a t e l y , p r o b a b l y i n few cases where f l o o d s now oc c u r w i l l i t be p o s s i b l e t o d i s p e n s e w i t h downstream e n g i n e e r i n g works such as the d y k i n g p r o j e c t s g o i n g on i n the F r a s e r V a l l e y . However, the v a l u e o f these works i n ' t h e i r p r e s e n t s t a t e can be g r e a t l y enhanced by the a d o p t i o n of p r o p e r s o i l and mois-t u r e c o n s e r v a t i o n p r a c t i c e s i n t h e headwaters. The water which a c c u m u l a t e s i n streams and r i v e r s may a r r i v e a t t h e low e r l e v e l s o r ocean i n two ways: e i t h e r as s u r f a c e r u n - o f f or from the ground water t a b l e i n the form of seepage water or s p r i n g s . I t i s o b v i o u s from the r e f e r e n c e s which have been made t h a t e x c e s s i v e r u n - o f f can be c o n t r o l l e d i n s p i t e of the c o m p l e x i t y of the h y d r o l o g i c c y c l e and hence the amount of r u n - o f f water which passes d i r e c t l y i n t o the r i v e r s c a u s i n g f l o o d s may be f a v o r a b l y i n f l u e n c e d . R eference has a l r e a d y been made t o the a c t i o n of t h e g r a s s c o v e r i n g u i d i n g r a i n w a t e r s a f e l y t o the underground s t o r a g e from which i t r e a p p e a r s over a p e r i o d of time from seepage and s p r i n g s , thus m a i n t a i n i n g a ste a d y s u p p l y t o the streams and r i v e r s r a t h e r than the sudden r u s h of r u n - o f f water t h a t f o l l o w s a q u i c k thaw or an - 93 -i n t e n s e downpour on a r e l a t i v e l y b a r r e n w a t e r s h e d . The a d o p t i o n of a sound g r a z i n g p o l i c y t o reduce r u n - o f f , s o i l w ashing and the maintenance of a good p r o t e c t i v e cover of v e g e t a t i o n are the b a s i s of e f f e c t i v e f l o o d c o n t r o l . The r e -d u c t i o n of the r u n - o f f w i l l mean t h a t more w a t e r i s p a s s i n g i n t o the s o i l and to the w a t e r t a b l e , t h a t streams w i l l have a s t e a d i e r s u p p l y ; the v e g e t a t i o n which f a c i l i t a t e s t h i s t r a n s i t g e n e r a l l y b e n e f i t s from t h e h i g h e r water t a b l e ( i n semi a r i d a r e a s ) and thus the v i c i o u s c y c l e of d e n u d a t i o n , e r o s i o n and f l o o d s can g r a d u a l l y be changed to a b e n e f i c i a l c y c l e of n a t u r a l r e - g r a s s i n g , s o i l and water r e t e n t i o n and the r e d u c t i o n or e l i m i n a t i o n of f l o o d s . U n f o r t u n a t e l y the p r o c e s s of d e g e n e r a t i o n i n a w atershed a r e a , r e s u l t i n g from o v e r g r a z i n g , may r e s u l t i n f l o o d damage i n an e x c e p t i o n a l l y s h o r t t i m e , w h i l e , as p r e v i o u s l y mentioned, the p r o c e s s e s of s o i l f o r m a t i o n and r e g e n e r a t i o n are slow. I t i s not the o b j e c t i v e of t h i s T h e s i s t o d i s c u s s i n d e t a i l a l l the r a m i f i c a t i o n s of s o i l e r o s i o n caused by o v e r -g r a z i n g but to i n d i c a t e the d i r e n e c e s s i t y of a c knowledging the s o i l as an e s s e n t i a l f a c t o r i n s t u d y i n g the e f f e c t s of any change which o v e r g r a z i n g p r a c t i c e s may e x e r t on the g r a z i n g biome. T h e r e f o r e , a f u r t h e r d i s c u s s i o n of the e f f e c t s of water e r o s i o n w i l l not be pursued. HYDROLOGICAL CYCLE ATMOSPHERIC VAPOR • PRECIPITATION SUBSOIL F i g u r e 17. - 95 -B. WIND EROSION ( l ) F a c t o r s I n f l u e n c i n g Wind E r o s i o n Wind e r o s i o n i n a s e r i o u s form i s c o n f i n e d t o a r i d r e g i o n s u s u a l l y below 15 i n c h e s i n p r e c i p i t a t i o n p e r y e a r . The most i m p o r t a n t reasons f o r t h i s are as f o l l o w s (214) : (a) V e g e t a t i o n i s l e s s dense because of l o w e r p r e c i p i t a t i o n ; (b) S o i l o r g a n i c m a t t e r i s l o w e r because of l e s s e r amounts of v e g e t a t i o n and h i g h e r s o i l t e m p e r a t u r e ; (c ) The h u m i d i t y o f the atmosphere i s lower and hence the s u r f a c e s o i l i s d r i e r ; (d) Hot, bare s o i l s cause r i s i n g a i r c u r r e n t s which l i f t s o i l p a r t i c l e s upward i n t o the more s w i f t l y moving atmosphere. Needless t o say, wind v e l o c i t y i s a v i t a l f a c t o r i n -f l u e n c i n g the degree of e r o s i o n . However, u n l e s s the s o i l and v e g e t a t i o n c o n d i t i o n s a r e conducive t o wind e r o s i o n , no s e r i o u s damage w i l l r e s u l t . S o i l t e x t u r e , j u s t as i n a r e a s s u b j e c t t o water e r o s i o n , i s one of the i m p o r t a n t f a c t o r s i n f l u e n c i n g i t s s u s c e p t i b i l i t y t o b l o w i n g (260). The p o p u l a r c o n c e p t i o n i s t h a t sandy l a n d s blow the most r e a d i l y , t h i s c o n c e p t i o n b e i n g founded p r o b a b l y upon t h e f a c t t h a t the b l o w i n g a r e a s are covered by sand. The f a c t t h a t the sand i s merely the mater-i a l t h a t has not blown away i s o v e r l o o k e d . Heavy p a r t i c l e s , o t h e r t h i n g s b e i n g e q u a l , w i l l blow the l e a s t r e a d i l y , and f i n e p a r t i c l e s the most r e a d i l y . However, t h i s i s s u e i s some-what confused by the f a c t t h a t sands are s i n g l e p a r t i c l e s and - 96 -are low i n o r g a n i c m a t t e r , whereas t h e f i n e t e x t u r e d s o i l s c l i n g t o g e t h e r to form l a r g e g r a n u l e s . The o r g a n i c c o n t e n t of s o i l s i s an i m p o r t a n t f a c t o r i n -f l u e n c i n g b l o w i n g . Though o r g a n i c m a t t e r i t s e l f i s l i g h t and very s u b j e c t t o b l o w i n g , i t t e n d s to b i n d s o i l p a r t i c l e s t o -g e t h e r and make them s t a b l e . L i k e w i s e , a h i g h o r g a n i c content means a h i g h water h o l d i n g c a p a c i t y , which d e c r e a s e s b l o w i n g . Organic c o n t e n t has been c a l l e d the most i m p o r t a n t s i n g l e f a c t o r d e t e r m i n i n g t h e degree of wind e r o s i o n (260). While Wyatt, S m i t h , Newton and G i l l i e s (260) c o n s i d e r o r g a n i c m a t t e r c o n t e n t the most i m p o r t a n t s i n g l e f a c t o r d e t e r -m i n i n g the degree of wind e r o s i o n , E l l i s (193) s t a t e s t h a t v e g e t a t i o n i s t h e most v i t a l s i n g l e element d e t e r m i n i n g the s u s c e p t i b i l i t y of a s o i l t o b l o w i n g . The w r i t e r b e l i e v e s the l a t t e r statement t o be more e x a c t i n g i n t h a t v e g e t a t i o n i n -d i r e c t l y i n f l u e n c e s s o i l s t r u c t u r e , s o i l o r g a n i c m a t t e r , s o i l m o i s t u r e , a t m o s p h e r i c h u m i d i t y and wind v e l o c i t y . I t i s through t h e s e mediums, t o g e t h e r w i t h m e c h a n i c a l b i n d i n g of the s o i l p a r t i c l e s , t h a t v e g e t a t i o n p r o t e c t s s o i l from b l o w i n g . The s t r u c t u r e of s o i l i s improved by r o o t a c t i o n , t o g e t h e r w i t h i n c r e a s e d o r g a n i c matter and r o o t f i b r e a c c u m u l a t i o n . In-s u f f i c i e n t r o o t f i b r e and l a c k o f c o h e s i o n between the s o i l p a r t i c l e s a re the more i m p o r t a n t f a c t o r s d e t e r m i n i n g t h e r e a d i -ness with- which s o i l blows, r o o t f i b r e s b e i n g much more im-p o r t a n t t h a n humus. The a c t i o n of v e g e t a t i o n i n d e c r e a s i n g wind v e l o c i t y a t the s o i l s u r f a c e i s w e l l known ( i n the form of t r e e rows) i n - 97 -windswept a r e a s . S i m i l a r e f f e c t s can be o b t a i n e d from the the use of s m a l l e r p l a n t s or even g r a s s swards. (2) R e s u l t s of Wind E r o s i o n Sheet e r o s i o n , as p r e v i o u s l y mentioned, may be e x p e c t e d t o a f f e c t the a c t i v i t y of the s o i l f l o r a by c hanging the n a t u r e and number of the organisms p r e s e n t , t h e amount and q u a l i t y of the o r g a n i c m a t t e r and the p h y s i c a l environment ( 1 4 8 ) . In some cases s o i l p a r t i c l e s have been known t o t r a v e l d i s t a n c e s of 1,000 to 2,000 m i l e s (85) and a c t u a l d e p o s i t measurements have shown 10.5 to 85 tons per square m i l e a f t e r a s i n g l e storm. The e x t r e m e l y s e r i o u s s o i l l o s s e s on farm and r a n g e l a n d s are o n l y one of the r e s u l t s of wind e r o s i o n . Damage t o vege-t a t i o n by a b r a s i o n and smothering caused by d e p o s i t i o n a r e sometimes s u f f i c i e n t to cause d e a t h . Exposure of r o o t s by b l o w i n g may k i l l p l a n t s ( 8 5 ) , e s p e c i a l l y d u r i n g the s e e d l i n g stage when they may be blown from t h e ground. The p r e v e n t i o n of wind e r o s i o n i s c o m p a r a t i v e l y s i m p l e but when i t has p r o g r e s s e d t o the stage of a c t i v e s o i l move-ment and w i d e s p r e a d d e p l e t i o n i t becomes one of the most f o r m i d a b l e problems f a c i n g the l a n d e c o l o g i s t . F o r t u n a t e l y , s o i l d r i f t i n g s t a r t s n o t o v er a wide a r e a but a t a s m a l l f o c a l spot from which the spread b e g i n s . A p a r t i a l vacuum i s c r e a t e d as wind passes over a s m a l l d e p r e s s i o n . o f bare s o i l , c a u s i n g an upward s w i r l i n g a i r c u r r e n t which c a r r i e s the s o i l p a r t i c l e s and causes an i n c r e a s i n g l y deep and wide blow-out h o l e . The m a t e r i a l i s c a r r i e d u n t i l the a i r v e l o c i t y i s - 98 -d e c r e a s e d , whereupon the l a r g e r p a r t i c l e s s e t t l e o ut. Thus dunes are formed a l o n g fence l i n e s or any o t h e r o b s t r u c t i o n . These dunes a r e r o l l e d by the wind, m a t e r i a l from the wind-ward s i d e b e i n g d e p o s i t e d on the p r o t e c t e d or l e e w a r d s i d e . Blow spots may be s t a r t e d because of some l o c a l s o i l c o n d i t i o n such as a sand s p o t , or t h e y may be cause by some mec h a n i c a l d i s t u r b a n c e such as i s found i n a s t o c k r o l l i n g p l a c e , a c o r r a l , or a roadway. An example of such an a r e a may be found i n the S w i f t C u r r e n t - Webb M u n i c i p a l i t i e s Community P a s t u r e . D u r i n g c a r r y i n g c a p a c i t y s t u d i e s i n the sand dune p o r t i o n of t h e community p a s t u r e i t was n o t e d t h a t t h e blow-out a r e a s were i n c r e a s i n g i n s i z e and t h a t c a t t l e t r a c k s gave ev i d e n c e of the r e p e a t e d presence of s t o c k i n t h a t a r e a (38). I t i s suggested t h a t s t o c k spend p a r t s of the e a r l y mornings on p o r t i o n s of the blow-out sand s i n c e t h e s e a r e a s warm more r e a d i l y than t h e areas covered w i t h a canopy of v e g e t a t i o n . I t i s the a u t h o r ' s o p i n i o n t h a t the a c t i v i t i e s o f t h e l i v e -s t o c k i n t h i s a r e a were among the prime f a c t o r s c o n t r i b u t i n g to the p r o d u c t i o n and spread of the dune shown i n F i g u r e s 18, 19 and .20. Wooden pegs and i r o n s t a k e s have been p l a c e d i n the path of t h e blow-out and a c a r e f u l s t u d y of the a c t i v i t i e s of t he blow-outs i s b e i n g conducted by the s t a f f of the Forage D i v i s i o n of t h e Dominion E x p e r i m e n t a l S t a t i o n , S w i f t C u r r e n t , Saskatchewan.(34)« The s o i l t h roughout the area i s c l a s s i f i e d as sand and u n d i f f e r e n t i a t e d dune sands (138) and the v e g e t a t i o n a s s o c i a -- 1 0 0 -t i o n contains such s p e c i e s as sandgrass ( C a l a m o v i l f a l o n g i -f o l i a Hook.), sand dropseed (Sporobolus c r y p t a n d r u s ) , Indian r i c e g r a s s (Oryzopsis hymenoides Roem. & S c h u l t ) , wolf w i l l o w (Elaeognus commutata Bernh.), choke cherry (Prunus melano-carpa A. N e l s . ) , and rose (Rosa spp.). The f i r s t p l a n t to enter the d i s t u r b e d s o i l appears to be the Indian r i c e g r a s s ( O r y z o p s i s hymenoides). 4 -F i g u r e 21. The Result of U n c o n t r o l l e d Wind E r o s i o n i n Southern Saskatchewan. Note the Pole and Wires. - 101 -A l b e r t s o n ( l ) s t a t e s t h a t dust blown from c u l t i v a t e d f i e l d s p r o b a b l y causes g r e a t e r damage th a n o v e r g r a z i n g . An extreme example of t h i s may be seen i n F i g u r e 21. T h i s p i c t u r e , t a k e n i n so u t h w e s t e r n Saskatchewan, shows Mr. W. A. Hubbard ( f o r m e r l y w i t h the Forage D i v i s i o n of the Dominion E x p e r i m e n t a l S t a t i o n , S w i f t C u r r e n t , Saskatchewan), h o l d i n g t e l e p h o n e w i r e s . The t o p of the telephone p o l e may be seen t o the l e f t of Mr. Hubbard. The s o i l (sand) d r i f t s i n the f o r e -ground have covered the road a l l o w a n c e . The l a n d behind Mr, Hubbard was f o r m e r l y g r a s s l a n d . These dunes are the r e s u l t of s o i l d r i f t i n g , not from o v e r g r a z i n g but from the c u l t i -v a t i o n of s o i l s t h a t were too l i g h t t o h o l d . When the e a r l y p i o n e e r s f i r s t s e t t l e d s o u t h e r n Saskatchewan t h e y home-steaded the l i g h t e r l a n d s because of the co m p a r a t i v e ease of pl o w i n g . With r e p e a t e d c e r e a l c r o p p i n g the o r g a n i c m a t t e r of the s o i l d e c r e a s e d and s o i l d r i f t i n g began. When the s o i l d r i f t e d t o the u n c u l t i v a t e d or g r a z i n g l a n d s the s o i l was h e l d by the f o l i a g e u n t i l w i t h s u c c e s s i v e storms the p l a n t cover was f i n a l l y i n u n d a t e d . Scenes such as the one p i c t u r e d i n F i g u r e 21 l e n d added weight t o A l b e r t s o n ' s ( l ) s t a t e m e n t . As i n t h e case of water e r o s i o n , the e f f e c t s of wind e r o s i o n a re both d e v a s t a t i n g and e x t e n s i v e . S i n c e the o b j e c t of t h i s T h e s i s i s to d e a l m a i n l y w i t h the r o l e p l a y e d by the v e g e t a t i o n under c o n d i t i o n s of o v e r g r a z i n g , i t i s suggested t h a t i f f u r t h e r examples of the r a m i f i c a t i o n s of wind e r o s i o n are d e s i r e d , F i g u r e 16 should be s t u d i e d . - 102 -, C. SUMMARY OF THE EFFECTS OF OVERGRAZING ON THE SOIL A g r a s s sward w e l l managed i s an e f f i c i e n t c o v e r f o r p r e v e n t i n g e r o s i o n and r e d u c i n g r u n - o f f ; a g r a s s sward badly-managed i s a dangerous t h i n g , w i t h the poor v e g e t a t i o n i n -c a p a b l e o f g u i d i n g the r a i n f a l l i n t o the s o i l , the bare ground f a v o u r i n g s o i l p a c k i n g from s e v e r a l c a u s e s , and the b e g i n n i n g of g u l l y e r o s i o n by water or the w h o l e s a l e removel of t o p s o i l by wind. A good sward has numerous m e r i t s from a c o n s e r v a t i o n p o i n t of v i e w . I t c o v e r s t h e s u r f a c e of the ground, p r o t e c t -i n g i t from t h e d i r e c t impact of the f a l l i n g r a i n d r o p s , t h u s k e e p i n g the pores of the s o i l open and capable of r e c e i v i n g e x c e s s i v e amounts of water. The l e a v e s o f the herbage a s s i s t i n g u i d i n g the f a l l i n g r a i n d r o p s to the s o i l . The humus l a y e r below t h e herbage i s capable of s t o r i n g many times i t s volume of w a t e r . I n t h i s way a good g r a s s sward f a v o u r s a h i g h degree of i n f i l t r a t i o n and ensures t h a t any water which does f l o w away as r u n - o f f i s c l e a r and has l i t t l e e r o d i n g power. The r o o t system of the g r a s s i s of v a l u e i n p r o t e c t i n g t h e s o i l a g a i n s t e r o s i o n , p a r t i c u l a r l y the a c t i o n of wind. O v e r g r a z i n g removes the p r o t e c t i v e v e g e t a t i v e c o v e r f o r the s o i l r e s u l t i n g i n the c o n d i t i o n s mentioned t h r o u g h o u t t h i s S e c t i o n . Some of the consequences of s o i l e r o s i o n on w e s t e r n r a n g e l a n d s i n the form of s o i l b l o w i n g and s o i l washing a r e : ( l ) t h e s i l t i n g and s e d i m e n t a t i o n of s t r e a m c h a n n e l s , r e s e r v o i r s , dams, d i t c h e s , and h a r b o u r s ; - 103 -(2) the l o s s of f e r t i l e s o i l m a t e r i a l i n d u s t storms; (3) the p i l i n g up o f s o i l on l o w e r s l o p e s and i t s d e p o s i t over a l l u v i a l plains,; the r e -d u c t i o n i n p r o d u c t i v i t y or o u t r i g h t r u i n of r i c h bottom l a n d s by t h e overwash of poor s u b s o i l m a t e r i a l such as sand and g r a v e l swept out of the h i l l s by streams of v a r y i n g i n t e n s i t y ; (4) det e r i o r a t i o n of s o i l and i t s f e r t i l i t y and t h e a s s o c i a t e d d e t e r i o r a t i o n of c r o p y i e l d s per a c r e and the v e g e t a t i o n grown t h e r e o n ; (5) l o s s of s o i l and w a t e r which causes t h e d e s t r u c t i o n of f o o d and cover f o r w i l d l i f e , i n c l u d i n g a b l o w i n g and washing of s o i l i n t o streams which s i l t over spawning beds as w e l l as d e s t r o y i n g w a t e r p l a n t s -- a food s u p p l y o f f i s h ; (6) a d i m i n i s h i n g of the underground water s u p p l y which i n t e n s i f i e s p e r i o d s of drought; (7) an i n c r e a s e i n the speed and volume of r a i n f a l l r u n - o f f , c a u s i n g severe and i n c r e a s i n g f l o o d s which b r i n g s u f f e r i n g , d i s e a s e and d e a t h ; (8) impoverishment of f a m i l i e s a t t e m p t i n g t o u t i l i z e e r o d i n g and eroded l a n d s ; (9) damage t o r o a d s , r a i l r o a d s and highways, farm b u i l d i n g s , f e n c e s , and o t h e r p r o p e r t y ; (10) l o s s e s i n n a v i g a t i o n , h y d r o e l e c t r i c power, m u n i c i p a l water s u p p l y , i r r i g a t i o n d e v e l o p -ments, f a r m i n g and g r a z i n g ; (11) i n c r e a s e s i n i n s e c t , r o d e n t , and o t h e r s m a l l a n i m a l p o p u l a t i o n s which may be c a r r i e r s of d i s e a s e s and p a r a s i t e s , thus endangering the d o m e s t i c g r a z i n g herds a l r e a d y weakened by s c a r c i t y of good f o r a g e . - 104 -V. OVERGRAZING AND WILDLIFE POPULATIONS The s i z e of domestic l i v e s t o c k p o p u l a t i o n s , i t has beai shown, are governed by t h e f o r a g e and w a t e r a v a i l a b l e on a range a r e a . So a l s o i t must be f o r w i l d l i f e p o p u l a t i o n s . Large amounts of f o r a g e may be l o s t t o commercial h e r d s through the a c t i v i t i e s of w i l d a n i m a l s . However, due t o the v a r y i n g degree of m o t i l i t y and the d e c i d e d w a r i n e s s of human a c t i v i t y , i t i s d i f f i c u l t t o e s t a b l i s h t h e f a c t t h a t w i l d l i f e competes w i t h the d o m e s t i c a t e d l i v e s t o c k f o r the a v a i l a b l e f o r a g e and water. The d e s t r u c t i o n o f p l a n t l i f e by i n s e c t s such as g r a s s h o p p e r s and l o c u s t s has been r e c o r d e d and mourned s i n c e b i b l i c a l days and has had a profound i n f l u e n c e on t h e development of the West. When the f o r a g e demands o f w i l d l i f e ;_are p l a c e d on a range a l r e a d y c a r r y i n g i t s f u l l c a p a c i t y of domestic l i v e s t o c k , o v e r g r a z i n g o f t e n r e s u l t s . W h i l e a t ti m e s grave l o s s e s of f o r a g e are s u f f e r e d by commercial h e r d s , the presence of w i l d l i f e s p e c i e s i s not o always c o n s i d e r e d t o t a l l y o b j e c t i o n a b l e . The q u e s t i o n may th e n be asked.: I f w i l d l i f e s p e c i e s compete w i t h domestic l i v e s t o c k of commercial v a l u e , how and when may they be con-s i d e r e d u n o b j e c t i o n a b l e and harmle s s ? S t o d d a r t and Smith (214) have c l a s s i f i e d n a t i v e h e r b i v o r o u s range a n i m a l s a c c o r d i n g t o s i z e and economic v a l u e . They c l a s s i f y t he fauna i n t o two - 105 -groups: (a) l a r g e mammals which are e c o n o m i c a l l y v a l u a b l e and hence t h e i r v a l u e must be weighed a g a i n s t t h e v a l u e of rhe f o r a g e t h e y consume; (b) s m a l l mammals, e s s e n t i a l l y r o d e n t s , whose e f f e c t s on range are p o p u l a r l y c o n s i d e r e d t o be s o l e l y d e s t r u c t i v e . A. LARGE RANGE WILDLIFE SPECIES The l a r g e h e r b i v o r e s found on r a n g e l a n d s i n c l u d e d e e r , e l k , moose, a n t e l o p e , b i g h o r n , mountain g o a t s and b i s o n . Today, f o r the most p a r t , o n l y the deer and e l k compete s e r i o u s l y w i t h d o m e s t i c a n i m a l s f o r range f o r a g e . Large a n i m a l s , o t h e r t h a n e l k and d e e r , u s u a l l y e x i s t e i t h e r i n a r e a s r e l a t i v e l y i n a c c e s s i b l e t o domestic l i v e s t o c k , or i n numbers so s m a l l t h a t they do not s e r i o u s l y compete f o r the a v a i l a b l e f o r a g e . They may a l s o e x i s t i n areas l a c k i n g ade-quate w a t e r i n g f a c i l i t i e s o r a v e g e t a t i o n p a l a t a b l e t o d omestic l i v e s t o c k . E l k ( c e r v u s c a n a d i e n s i s ) , l i k e c a t t l e , are f u n d a m e n t a l l y g r a s s e a t e r s (172, 201),, a l t h o u g h browse and f o r b s may a t times c o n s t i t u t e a p o r t i o n of the d i e t . F or t h i s r e a son i t may be seen t h a t e l k do compete w i t h d o m e s t i c a t e d l i v e s t o c k . Recent s t u d i e s by P i c k f o r d (157), of the U n i t e d S t a t e s P a c i f i c Northwest F o r e s t and Range Experiment S t a t i o n , have r e v e a l e d t h a t a band of 300 e l k consumed t w o - t h i r d s as much range f o r -age as a band of 900 ewes and lambs d u r i n g a three-month g r a z i n g season on a summer range a l l o t m e n t of the Whitman " a t i o n a l F o r e s t . These s t u d i e s a l s o r e v e a l e d t h a t the t e n - 106 -range p l a n t s which made .up 80 p e r c e n t of the sheep d i e t a l s o made up 80 p e r c e n t of the e l k d i e t . These s t r i k i n g d a t a add much weight t o the stockmen's arguments t h a t the r e d u c t i o n of domestic l i v e s t o c k numbers i s o n l y a p a r t i a l c o n t r o l of o v e r -g r a z i n g i n a r e a s where e l k are numerous. I n d i v i d u a l l y , the c o m p e t i t i o n from deer f o r a v a i l a b l e f o r a g e does not appear to be as c r i t i c a l as t h a t from e l k ; however, the deer . p o p u l a t i o n i s much g r e a t e r t h a n t h a t of the e l k i n B r i t i s h Columbia and most o t h e r range a r e a s . In A r i z o n a , Rasmussen (166) found t h a t browse p l a n t s were c o m p l e t e l y g r a z e d out by deer w h i l e g r a s s s p e c i e s were m a i n t a i n e d . However, Dixon (73) found t h a t Mule Deer consume l a r g e r amounts of g r a s s when f o r b s and browse are s c a r c e and when the g r a s s i s green and s u c c u l e n t . Lack of s p r i n g g r a z i n g , a c c e l e r a t e d by premature g r a z i n g by d e e r , i s one of the f a c t o r s c o n t r i b u t i n g t o the i n c r e a s i n g c o s t of r a n g i n g d o m e s t i c g r a z i n g a n i m a l s . I n s p i t e of the f a c t t h a t a n t e l o p e are n a t i v e s of the p r a i r i e s and i n t e r m o u n t a i n p l a i n s , g r a s s does not seem to con-s t i t u t e much of t h e i r d i e t . Coney (51), i n s t u d y i n g a n t e l o p e foods d u r i n g the f a l l g r a z i n g p e r i o d , found t h a t g r a s s e s com-p r i s e d o n l y 6.0 p e r c e n t of the d i e t . The o t h e r c o n s t i t u e n t s i n c l u d e d m a i n l y browse (87-4 p e r c e n t ) and weeds (5.7 p e r c e n t ) . The economic and s o c i a l problems a s s o c i a t e d w i t h the com-p e t i t i o n between game and l i v e s t o c k a r e not based s o l e l y on the amount of a v a i l a b l e f o r a g e . Steepness and l a c k o f w a t e r (213) cause many ranges to be l i t t l e used by l i v e s t o c k and on t h e s e a r e a s , c o m p e t i t i o n i s not s e r i o u s . On l i m i t e d s p r i n g - 107 -range, such as i s the case i n most of the w e s t e r n range a r e a s and B r i t i s h Columbia i n p a r t i c u l a r , the problem may be a c u t e . In the case of^fdeer, because of the d i e t a r y d i f f e r e n c e s ( e x c e p t d u r i n g s p r i n g g r a z i n g ) and the d i f f e r e n c e s i n the ranges, t h e y graze i t would be n e c e s s a r y t o remove 10 t o 50 deer t o make room f o r one more s t e e r (213). ( C o m p e t i t i o n i s much i n t e n s i -f i e d by e x c e s s i v e numbers of e i t h e r game or l i v e s t o c k . ) The removal of such h i g h numbers o f game would cause c o n s i d e r a b l e a l a r m among the sportsmen. Table VI shows the revenue i n B r i t i s h Columbia d e r i v e d f r o m h u n t i n g l i c e n c e s and f e e s a l o n e (25). The amounts spent on equipment, g u i d e s , and accommoda-t i o n f o r the hunters, i s many t i m e s g r e a t e r . TABLE VI Revenue from Sale of Game i n B r i t i s h L i c e n c e s and Fees (25) Columbia Year F i n e s Revenue from L i c e n c e s and Fees 1943 1944 1945 1946 $ 5,554.50 5,570.50 8,381.50 10,921.00 $ 207,661.72 238,902.36 352,228.85 502,555.25 T o t a l 1913-46 $199,387.07 $ 5,390,972.23 I n r e v i e w i n g the h i s t o r y of game i n B r i t i s h Columbia, Brooks (26) s t a t e s t h a t i n the e a r l y days t h e r e were r e l a t i v e j y s m a l l numbers o j ^ i e e r . S u b s e q u e n t l y , l a r g e numbers of deer m i g r a t e d to the Kootenays and t h e Okanagan. With them came the mountain l i o n . These mountain l i o n s have been known t o a t t a c k herds of w i n t e r i n g c a t t l e c a u s i n g c o n s i d e r a b l e damage. - 108 -Because the game are owned by the f e d e r a l and p r o v i n c i a l governments t h e y have a tendency t o r e a c h l a r g e numbers i n such p r o t e c t e d p l a c e s as t h e J a s p e r , B a n f f , and o t h e r l a r g e n a t i o n a l and p r o v i n c i a l p a r k s . However, when w i n t e r c l o s e s i n , the tendency i s f o r t h e game to m i g r a t e t o v a l l e y bottoms such as the Rocky Mountain Trench. Here they c o n c e n t r a t e i n l a r g e numbers, compete s e r i o u s l y w i t h t h e w i n t e r d o m e s t i c l i v e s t o c k and o f t e n are r e s p o n s i b l e f o r s e r i o u s damage t o s t o r e d emergency f e e d such as hay and un t h r a s h e d g r a i n . T h i s s i t u a t i o n i s a c o n s t a n t worry t o the stockmen of the E l c o -Waldo and Windermere a r e a s , where w i n t e r f e e d and s p r i n g range i s n o t abundant. Many d i s e a s e s and p a r a s i t e s common t o deer a l s o o c c u r i n domestic range a n i m a l s ( 1 0 6 ) . I n C a l i f o r n i a , f o r example, the i n t e s t i n a l round-worms found i n deer have a d i r e c t l i f e c y c l e . On ranges i n t e n s i v e l y g r a z e d by deer and sheep and c a t t l e , the domestic s p e c i e s o f t e n i n g e s t l a r v a l worms. While the domestic l i v e s t o c k are t r e a t e d w i t h d r u g s , t h e i r r e l i e f can o n l y be c o n s i d e r e d temporary s i n c e l i t t l e can be done to c o n t r o l the i n f e s t a t i o n s i n deer. I n the c o n t r o l of deer p a r a s i t e s two methods can be employed: (a) The game a n i m a l s can be a t t r a c t e d away from t h e domestic l i v e s t o c k r anges. (b) Both the deer and domestic l i v e s t o c k numbers must be reduced. The problems of i n t e r r e l a t i o n s h i p s between domestic and n a t i v e g r a z i n g a n i m a l s cannot be r e a d i l y s o l v e d because o f the d i v e r s i t y of i n t e r e s t s and v a l u e s i n v o l v e d . Domestic INTERRELATIONS IN A NATURAL BIOME H O NO F i g u r e 22. - 110 -l i v e s t o c k cannot be e l i m i n a t e d f r o m crown or p u b l i c g r a z i n g l a n d s w i t h o u t d r a s t i c economic changes. Nor can t h e game be e l i m i n a t e d w i t h o u t u p s e t t i n g t h e p u b l i c i n g e n e r a l and the hunters i n p a r t i c u l a r . Only t h r o u g h the c o - o p e r a t i o n o f the stockmen, c o n s e r v a t i o n i s t s and sportsmen can problems of t h i s type be s o l v e d . They must s t u d y l i v e s t o c k numbers, game numbers, range c o n d i t i o n s , h u n t i n g c o n d i t i o n s and economic c o n d i t i o n s , and then o n l y a f t e r c a r e f u l l y i n t e g r a t i n g a l l t h e s e f a c t o r s w i l l they be a b l e t o make s c i e n t i f i c a l l y sound d e c i s i o n s . B. SMALL RANGE WILDLIFE SPECIES In c o u n t l e s s i n s t a n c e s the d e t e r i o r a t i o n of t h e g r a z i n g a r e a s of the West i s d e p i c t e d by d e s o l a t i o n , d u s t , b l e a c h e d s k e l e t o n s and almost i n v a r i a b l y a gopher s i t t i n g on i t s haunches b e s i d e i t s burrow. The a r t i s t i n p o r t r a y i n g h i s scene may not have been aware of the a c t u a l p a r t p l a y e d by t h e s e s m a l l mammals. No range a r e a i s f r e e of t h e presence of t h e s e a n i m a l s which a r e today the s u b j e c t of some of t h e most i m p o r t a n t d i s c u s s i o n s c o n c e r n i n g p r o p e r range management. S i n c e many of them consume p r i n c i p a l l y the same f o r a g e s p e c i e s as the domestic g r a z i n g a n i m a l s and s i n c e t h e i r burrows have c o n t r i b u t e d to numerous broken l e g s f o r a l l c l a s s e s o f s t o c k , t h e s e s m a l l a n i m a l s are u s u a l l y c o n s i d e r e d w i t h g r e a t d i s -f a v o u r by stockmen. Nor are t h e y a c c e p t e d by f a r m e r s and g r a i n growers who l o s e much of t h e i r crop each y e a r . A b i b l i o g r a p h y p u b l i s h e d i n 1936 (171) c o n t a i n s 8 , 2 7 4 i m p o r t a n t - I l l -books, a r t i c l e s and o t h e r p u b l i c a t i o n s d e a l i n g w i t h the management' of western r a n g e s , l i v e s t o c k and w i l d l i f e . I t i s i n t e r e s t i n g to note t h a t of t h e s e , 216 come under the t i t l e of " C o n t r o l of R a n g e - d e s t r o y i n g Rodents". I t i s ob v i o u s t h a t the m a j o r i t y o f the a u t h o r s p r i o r to about 1939 r e g a r d e d r o d -ents and o t h e r s m a l l mammals i n a v e r y b a l e f u l l i g h t . I t i s s u r p r i s i n g to d i s c o v e r t h a t u n t i l t h a t time v e r y few i n -v e s t i g a t o r s seemed to r e a l i z e t h a t an a n i m a l , even though a r o d e n t , may p o s s i b l y do more t h a n one t h i n g j i n o t h e r words, t h a t a cause may have more than one e f f e c t and an e f f e c t more than one cause. ( l ) D e t r i m e n t a l E f f e c t s o f S m a l l G r a z i n g Mammals Jack r a b b i t s appear t o p r e f e r p l a n t s i n the o r d e r of weeds, g r a s s e s and browse, w i t h t h e f i r s t two making up a major and about e q u a l p a r t o f the d i e t (5). The e q u a l p o r t i o n of weeds and g r a s s i n the d i e t o f f e r s the e x p l a n a t i o n as t o why r a b b i t s a r e more abundant on o v e r g r a z e d than on normal r a n g e s . A r n o l d s u g g e s t s t h a t once d e t e r i o r a t i o n i s w e l l under way, r a b b i t s may be a p a r t i a l cause o f o v e r g r a z i n g , w h i l e i n the f i n a l s t a g e s of d e t e r i o r a t i o n t hey may be the p r i m a r y cause of d e p l e t i o n . Under normal c o n d i t i o n s (28) the r a b b i t p o p u l a -t i o n of mixed g r a s s p r a i r i e i s one j a c k r a b b i t and one c o t t o n -t a i l per a c r e . The j a c k r a b b i t s g r a z i n g i n terms of cows (5) i s : 62 t 7 A r i z o n a r a b b i t s B one 1000 l b . cow 48 t 2 A n t e l o p e r a b b i t s = one 1000 l b . cow. - 112 -T a y l o r , V o r h i e s and L i s t e r (225) found t h a t o n l y 15 a n t e l o p e j a c k r a b b i t s would be r e q u i r e d to eat as much v a l u a b l e range f o r a g e as one sheep, o r 74 as much as one cowj t h a t 30 A r i z o n a j a c k r a b b i t s would, eat as much as one sheep and 148 as much as one cow. I t may be n o t e d t h a t the apparent d i s -crepancy i n the e q u i v a l e n t s i s e x p l a i n e d t h a t T a y l o r e t a l . made t h e i r c a l c u l a t i o n s on v a l u a b l e f o r a g e amounts, w h i l e A r n o l d ' s c a l c u l a t i o n s were based on t o t a l f o r a g e comsumption by the r a b b i t s . I t was a l s o noted (225) t h a t g r a s s made up 45 p e r c e n t of the d i e t of t h e a n t e l o p e j a c k r a b b i t and 24«1 p e r c e n t of t h a t of the A r i z o n a j a c k r a b b i t . I t would not appear t h a t the amount of v a l u a b l e f o r a g e consumed by t h e s e r a b b i t s s h o u l d c o n s t i t u t e such an a l a r m i n g amount when under normal C o n d i t i o n s the r a b b i t p o p u l a t i o n i s o n l y 2 p e r a c r e . U n f o r t u n a t e l y , under c o n d i t i o n s of o v e r -g r a z i n g the p o p u l a t i o n i n c r e a s e s ( T a b l e V I I ) and the amounts of v a l u a b l e f o r a g e a v a i l a b l e t o domestic l i v e s t o c k d e c r e a s e . The reasons f o r t h e s e i n c r e a s e d numbers of r a b b i t s may be ( 2 2 5 ) : (a) They p r e f e r a n n u a l shoots and weeds to o l d g r a s s (b) The added v i s i b i l i t y i n t h e o v e r g r a z e d a r e a s i s an advantage to the r a b b i t s . In o v e r g r a z e d a r e a s where so many domestic a n i m a l e q u i -v a l e n t s may appear i n the form of r a b b i t s , the q u e s t i o n may a r i s e : "Can the range be r e h a b i l i t a t e d i f j a c k r a b b i t s a r e p r e s e n t ? " There can be no one answer t o t h i s q u e s t i o n , f o r l o c a l c o n d i t i o n s w i l l govern the answer t o a c o n s i d e r a b l e - 1 1 3 -degree. Where l i v e s t o c k p r e s s u r e i s moderate and the vege-t a t i o n c l o s e to a b a l a n c e between improvement and d e t e r i o r a -t i o n , the r a b b i t p o p u l a t i o n might t i p the s c a l e downward. Where the l i v e s t o c k p r e s s u r e i s heavy, i t s e f f e c t s w i l l be preponderant and j a c k r a b b i t e f f e c t s may i n c r e a s e the s e r i o u s -ness of the s i t u a t i o n . Some i n v e s t i g a t o r s go as f a r as t o s t a t e t h a t an attempt at a r t i f i c i a l r e s e e d i n g w i t h o u t r a b b i t c o n t r o l i s i n a d v i s a b l e , w h i l e some b e l i e v e t h a t r a b b i t s may be a b l e t o keep a range i n a c o n s t a n t s t a t e of d e t e r i o r a t i o n . The w r i t e r has not been a b l e t o f i n d v e r i f i c a t i o n or i n s t a n c e s i n t h e l i t e r a t u r e to s u p p o r t t h e s e l a t t e r v i e w s , a l t h o u g h i t i s t h e o r e t i c a l l y f e a s i b l e t h a t such may be the c a s e . Ever p r e s e n t i n a r e a s w i t h l a r g e numbers of r a b b i t s and r o d e n t s i s the p o s s i b i l i t y of c o n t r a c t i o n and s p r e a d of t u l a r e m i a (caused by the organism P a s t e u r e l l a t u l a r e n s i s ) among the r a b b i t p o p u l a t i o n , thus endangering the l i v e s and h e a l t h of the r e s i d e n t s of such a g r a z i n g a r e a ; a f u r t h e r r a m i f i c a t i o n of the e f f e c t s of o v e r g r a z i n g . To the w r i t e r ' s knowledge, the o n l y p r a i r i e dog "town" i n Canada i s found near V a l M a r i e , Saskatchewan, and t h e r e f o r e does not c o n s t i t u t e much of a problem. In the U n i t e d S t a t e s , however, the p r a i r i e dog i s one of the most d e s t r u c t i v e r o d e n t s i n the western g r a z i n g r e g i o n s . T a y l o r and L o f t f i e l d (224) c l a i m t hey d e s t r o y as h i g h as 80 p e r c e n t of the a v a i l a b l e g r a s s e s and are of no b e n e f i t t o the biome*whatsoever. They found t h a t a t o t a l p r o d u c t i o n of a p p r o x i m a t e l y 2,250 pounds x S e e Appendix A - 114 -per a c r e of the i m p o r t a n t f o r a g e g r a s s e s , over 1800 pounds were consumed by the p r a i r i e dogs. The i n v e s t i g a t i o n showed t h a t the p r a i r i e dogs and c a t t l e eat the same p l a n t s p e c i e s and i n the same o r d e r of p r e f e r e n c e . I t may t h e r e f o r e be seen t h a t the p r a i r i e dog does n o t h i n g t o a s s i s t i n o v e r -coming the e f f e c t s o f o v e r g r a z i n g , w h i l e i t does c o n t r i b u t e t o such a s i t u a t i o n . I t does not seem p r o b a b l e t h a t t h e r e would be any i n c r e a s e i n the numbers of p r a i r i e dogs under o v e r -g r a z i n g because of the s h o r t a g e of p a l a t a b l e s p e c i e s under such c o n d i t i o n s . S u p e r v i s o r Simpson (168) of the Cochetopa N a t i o n a l F o r e s t has r e p o r t e d t h a t t h e e l i m i n a t i o n o f p r a i r i e dogs from t h a t f o r e s t has r e s u l t e d i n : (a) c h e c k i n g e x t e n s i v e e r o s i o n ; (b) r e c l o t h i n g denuded a r e a s ; ( c ) e l i m i n a t i n g f o r a g e l o s s e s ; (d) i n c r e a s i n g f o r a g e enough t o c a r r y an a d d i t i o n a l 2,000 head of sheep and 500 c a t t l e ; (e) e l i m i n a t i n g l o s s e s i n la m b i n g through broken l e g s . Shaw, i n s t u d y i n g the Columbia ground s q u i r r e l , found t h a t i t was d e s t r u c t i v e to both p a s t u r e and h a y l a n d s . E x p e r i -ments (185) conducted i n the summer of 1913 showed t h a t a ground s q u i r r e l a t e one-seventh of a pound or 17.2 p e r c e n t of i t s body w e i g h t d a i l y . At t h i s r a t e 385 s q u i r r e l s would con-sume the p a s t u r e of one cow or 96 s q u i r r e l s would devour the p a s t u r e of one sheep i n the same t i m e . I n a complete e r a d i c a -t i o n experiment conducted i n a r a v i n e p a s t u r e i t was found - 115 -t h a t the p o p u l a t i o n was 10 s q u i r r e l s per a c r e . I n o t h e r a r e a s i t was noted to be as h i g h as 75 per a c r e . With p o p u l a t i o n s as h i g h as 25 per a c r e , t h e s q u i r r e l s i n an a r e a of f o u r a c r e s would be a b l e to consume the f o r a g e t h a t would n o r m a l ^ s a t i s f y one sheep. L i k e j a c k r a b b i t s , ground s q u i r r e l s are e s p e c i a l l y f a v o r e d when the t a l l e r g r a s s e s are e l i m i n a t e d l e a v i n g a dense mat o f s h o r t g r a s s e s and clumps of f o r b s ( T a b l e V I I I ) . I t i s agreed (115, 163) t h a t the ground s q u i r r e l s i n c r e a s e i n numbers under c o n d i t i o n s of moderate but tend t o decrease under c o n d i t i o n s of s e v e r o v e r -g r a z i n g accompanied by e r o s i o n . The cause of the d e c r e a s e a t t h i s stage i n the p l a n t s u c c e s s i o n i s p r o b a b l y due t o the l a c k of p a l a t a b l e f o r a g e . The R i c h a r d s o n ground s q u i r r e l , which i s commonly found i n A l b e r t a , i s h a r m f u l i n a d d i t i o n to the amount, of f o r a g e i t consumes. S t u d i e s by Brown and Roy (29) have shown t h a t both the s q u i r r e l s themselves and the e c o p a r a s i t e s l i v i n g on them are c a r r i e r s of t h e S y l v a t i c o r Bubonic Plague ( P a s t e u r e l l a  p e s t i s ) , Rocky Mountain S p o t t e d Fever (Dermacentroxenus  t i c k e t t s i ) , and T u l a r a e m i a ( P a s t e u r e l l a t u l a r e n s i s ) . Gwatkin (96) has a l s o demonstrated t h a t t h e r e were e v i d e n c e s of t h e S l e e p i n g S i c k n e s s v i r u s (Equine E n c e p h a l o m y e l i t i s ) i n the b r a i n of some R i c h a r d s o n ground s q u i r r e l s . I n c r e a s e s i n the c o n c e n t r a t i o n of t h e s e r o d e n t s as a r e s u l t of o v e r g r a z i n g c o u l d r e a d i l y enharce the r a p i d spread and outbreak of any of t h e s e s e r i o u s d i s e a s e s . - 116 -TABLE V I I C o n c e n t r a t i o n of R i c h a r d s o n Ground S q u i r r e l s i n S o u t h e r n A l b e r t a ( 2 3 1 ) . LAND ANIMALS/A BURROWS/A ANIMALS/SECTION P r a i r i e 8 64 5,120 Abandoned 6 48 3,840 G r a s s l a n d 5 40 3,200 C u l t i v a t e d 3 24 1,920 24 192 Average 5 40 3,200 A f u r t h e r danger to l i v e s t o c k i s a f f o r d e d i n t h a t each s q u i r r e l has i t s own burrow and each burrow averages 8 open-i n g s i n an ar e a of 10 t o 15 f e e t i n d i a m e t e r . U n l e s s the l i v e s t o c k a r e wary, many broken l e g s may r e s u l t i n such a r e a s . I n s t u d y i n g the mied g r a s s p r a i r i e of Oklahoma, and the e f f e c t s o f o v e r g r a z i n g upon i t , Smith (200) found t h a t the t o t a l number of s p e c i e s of s m a l l a n i m a l s i s g r e a t e s t i n u n d i s -t u r b e d p r a i r i e and l e a s t i n o v e r g r a z e d and eroded a r e a s . The s m a l l e s t p o p u l a t i o n s of a l l s m a l l mammals i s reached i n the s e v e r e l y o v e r g r a z e d but uneroded a r e a s and a g a i n i n c r e a s i n g when e r o s i o n b e g i n s and new p l a n t s i n v a d e the community. An i m a l s f a v o u r e d by a s p a r s e , weedy v e g e t a t i o n show t h e i r g r e a t e s t abundance on the eroded a r e a s . In t h i s group a re found the deer mice, p i c k e t mice and c o t t o n t a i l r a b b i t s . Table V I I I shows the r e l a t i v e abundance of the v a r i o u s s m a l l mammals c o n s i d e r e d i n Smith's s t u d y . Abundance i s i n d i c a t e d by a s c a l e of 1 t o 5. One i n d i c a t e s an i n f r e q u e n t or r a r e species:,, w h i l e 5 i n d i c a t e s g r e a t abundance. T h i s method i s f r e q u e n t l y used to put such d a t a on a compar a t i v e b a s i s . TABLE V I I I R e l a t i v e Abundance of S m a l l Mammals on Mijed Grass P r a i r i e (75) i n Oklahoma ANIMAL NORMAL PRAIRIE PROPERLY GRAZED • SOMEWHAT OVERGRAZED NOT ERODED HEAVILY OVERGRAZED SOMEWHAT ERODED HEAVILY OVERGRAZED AND ERODED Deer mouse 3 4 1 3 5 Harv e s t mouse 1 2 1 1 0 Pock e t mouse 0 1 1 . 1 1 House mouse 1 1. 0 0 0 Cott o n r a t 2 0 0 0 0 Shrew 1 1 0 0 0 C o t t o n t a i l 2 3 3 . 3 4 Jack r a b b i t 1 1 2 3 2 Ground s q u i r r e l 1 1 2 2 0 Mole 1 1 0 0 0 Gopher 1. 2. '1 0 0 - 118 -(2) B e n e f i c i a l E f f e c t s of S m a l l G r a z i n g Animals As i n d i c a t e d , range r o d e n t s p r e f e r as food p l a n t s w h i c h are e a r l y i n the s u c c e s s i o n . Under some c i r c u m s t a n c e s ( 2 0 ) , the r o d e n t may a s s i s t i n overcoming the e f f e c t s o f o v e r g r a z i n g by s peeding up the p l a n t s u c c e s s i o n . T h i s i s done by l e s s e n -i n g the c o m p e t i t i o n between the c l i m a x p e r e n n i a l g r a s s e s and the f o r b s w h i c h some r o d e n t s f i n d more p a l a t a b l e . Thus, w h i l e t h e s e r o d e n t s may p r e v e n t the r e c o v e r y o f a b a d l y d e t e r -i o r a t e d range, t h e y may a l s o speed up t h e r e c o v e r y r a t e of ranges t h a t a r e not i n as poor c o n d i t i o n . The main b e n e f i c i a l f u n c t i o n s performed by the s m a l l mammals appear to be t h o s e of s o i l improvement. Indeed, i t would seem a l s o t h a t the o n l y o t h e r b e n e f i c i a l f u n c t i o n c a r r i e d on by t h e s e a n i m a l s i s to d i v e r t p r e d a t o r s away from v a l u a b l e game and l i v e s t o c k . A l t h o u g h the importance of a n i m a l s i n s o i l f o r m a t i o n i s r e c o g n i z e d and b r i e f l y mentioned under the t i t l e of " b i o l o g i c a l f o r c e s " , l i t t l e d a t a has been p r e s e n t e d t o show j u s t how i m p o r t a n t these f a c t o r s might be. G r i n n -d e l l (95) b e l i e v e s t h a t the presence of t h e s e s m a l l mammals b r i n g s t o the n a t i v e p l a n t s a s s o c i a t e d w i t h them q u i t e the same s o r t s of e f f e c t s as the f a r m e r produces by h i s " a r t i f i -c i a l " c u l t i v a t i o n of the c rop he r a i s e s . And the r o d e n t s and o t h e r s m a l l a n i m a l s , be i t n o t e d , l i k e w i s e take pay, i n t h e form of seeds, f r u i t , l e a v e s , stems, and r o o t s . I t i s b e l i e v e d by many i n v e s t i g a t o r s t h a t the n a t i v e s m a l l mammal burrowers c o n t r i b u t e to the optimum w e l f a r e of - 119 -the p l a n t a s s o c i a t i o n s i n the f o l l o w i n g ways: r (a) Weathering of the s u b s t r a t u m i s promoted by burrow systems w h i c h c a r r y a i r and water w i t h ^ c o n t a i n e d s o l v e n t s t o the s u b s o i l - a n d p a r e n t masses below (95). By t h e i r presence the deepening of t h e s o i l i s h a s t e n e d . (b) S u b s o i l i s brought to the s u r f a c e , where i t i s spread out by the a c t i o n of the a n i n i a l s , the wind and r a i n , s u b j e c t e d t o f u r t h e r w e a t h e r i n g and f i n a l l y i n c o r p o r a t e d w i t h t h e t o p s o i l . Bond and B o r e l l (2l) s t a t e t h a t gophers i n Yosemite N a t i o n a l Park a n n u a l l y move an average o f 3*6 tons of e a r t h per square m i l e from underground to the s u r f a c e . ( c ) The a c t i v i t i e s of bu r r o w i n g a n i m a l s on ground t h a t i s not o v e r g r a z e d t e n d s t o p r e v e n t e r o s i o n . D u r i n g storms or r a p i d thaws, the burrows form e n t r y ways f o r the water l e a d i n g i t i n t o the porous ground f o r f u r t h e r slow d i s t r i b u t i o n t h e r e (2l). U n f o r t u n a t e l y , i n some i n s t a n c e s , r o d e n t s accompanied by o v e r -g r a z i n g have been shown t o be the p r i m a r y causes of e r o s i o n . (d) P l a n t m a t e r i a l i s c a r r i e d by the r o d e n t s i n t o t h e i r burrows where i t c o n t r i b u t e s t o form o r g a n i c m a t t e r i n t h e d r y w e s t e r n s o i l s t h a t are g e n e r a l l y d e f i c i e n t i n o r g a n i c m a t t e r (222). (e) The a c t i v i t i e s of roden t s i n c r e a s e the s u p p l y of a v a i l a b l e n i t r o g e n and o t h e r s o i l n u t r i e n t s . Greene and Reynard (90) b e l i e v e t h a t the average n i t r o g e n v a l u e of the Kangaroo r a t burrow i s 31.5 c e n t s , w h i l e t h a t of the wood r a t i s 10 c e n t s . The rode.nt p o p u l a t i o n of the Santa R i t a Range Reserve i s e s t i m a t e d at 2,000,000, of which about 500,000 are wood r a t s and 100,000 are Kangaroo r a t s (223). The v a l u e of the n i t r o g e n from these two r o d e n t s i n t h a t a r e a alone would then be 81,500 d o l l a r s . ( f ) The mechanical l o o s e n i n g of the ground t h r o u g h the a c t i v i t i e s of bu r r o w i n g a n i m a l s makes f o r t h r i f t y p l a n t growth. T h i s h e l p s t o combat the compacting e f f e c t of l i v e s t o c k f e e t , e s p e c i a l l y when the s o i l i s wet (94). - 120 -I f the e f f e c t s of t h e s e s m a l l mammals are i m p o r t a n t t o the r a n g e l a n d biome as t h e s e i n v e s t i g a t o r s ( 9 0 , 95, 94, 222, 25, 155) would l e a d us t o b e l i e v e i t may w e l l prove t h a t t h e i r i n c r e a s e i n numbers under c o n d i t i o n s of o v e r g r a z i n g i s b e n e f i c i a l r a t h e r than d e t r i m e n t a l . Only the p r e p o n d e r a n t l y b e n e f i c i a l e f f e c t s of t h e s e a n i m a l s has been d i s c u s s e d i n t h i s s u b - s e c t i o n . I t i s v e r y d i f f i c u l t t o form any o p i n i o n as t o whether, i n the f i n a l a n a l y s i s , t h e s e a n i m a l s a re e c o n o m i c a l l y b e n e f i c i a l or d e t r i m e n t a l under c o n d i t i o n s of o v e r g r a z i n g . When r a n g e l a n d f o r a g e s are p r o p e r l y h a n d l e d , t h e r e i s a s l i g h t excess of f o r a g e above a l l needs f o r l i v e -s t o c k o r f o r watershed p r o t e c t i o n except i n a b n o r m a l l y d r y seasons. C o n s e q u e n t l y , the consumption of f o r a g e by t h e s e a n i m a l s i s p r o b a b l y of l i t t l e economic i m p o r t a n c e except on o v e r g r a z e d ranges or i n e x t r e m e l y dry seasons. A p a r t of t h i s f o r a g e i s s t o r e d by the a n i m a l s i n t h e i r burrows, and a s m a l l p a r t of the food consumed i s r e t u r n e d t o the s o i l i n the e x c r e t a of the a n i m a l s . T h i s adds t o the f e r t i l i t y of the s o i l and i n a d d i t i o n t h e r e a r e a l s o t h e p h y s i c a l e f f e c t s mentioned t h a t a r e produced by the b u r r o w i n g of the a n i m a l s and the pro b a b l e i n c r e a s e of phosphorus a v a i l a b l e f o r p l a n t use ( 9 0 ) . Under p r e s e n t c o n d i t i o n s , e xcept where t h e s i t u a -t i o n becomes a c u t e , i t w i l l p r o b a b l y be b e s t t o await t h e r e s u l t s of f u r t h e r s t u d i e s b e f o r e i n i t i a t i n g any w i d e s p r e a d recommendations. U n t i l then the economic s t a t u s cannot be v e r i f i e d under o v e r g r a z e d or even normal c o n d i t i o n s a l t h o u g h i t does not seem i m p o s s i b l e t h a t the b e n e f i c i a l e f f e c t s may - 121 -e q u a l the i n j u r i o u s e f f e c t s of t h e s e s m a l l range mammals. C. HARMFUL RANGE INSECTS The d e s t r u c t i v e a c t i v i t i e s , of g r a s s h o p p e r s a r e c o n s i d e r -ed among the f o u r c h i e f causes of r a n g e l a n d d e t e r i o r a t i o n (240). The o t h e r s a r e : severe l o n g c o n t i n u e d drought, o v e r -g r a z i n g , and b u r i a l by dust or e r o s i o n . D i b b l e (7l) found t h a t s e v e r e grasshopper i n f e s t a t i o n s , p a r t i c u l a r l y on the 1 l i g h t e r s o i l s , have been a major c o n t r i b u t i n g f a c t o r i n s o i l e r o s i o n . U n f o r t u n a t e l y , because of i t s s i z e and the more s p e c t a c u l a r e f f e c t s t h a t g r a s s h o p p e r i n f e s t a t i o n s have on c e r e a l c r o p s , many r a n c h e r s i g n o r e or do not a p p r e c i a t e the w i d e s p r e a d damage caused by these i n s e c t s . A l l r e d (4) noted t h a t the c o l l a b o r a t i o n of heavy g r a s s h o p p e r i n f e s t a t i o n s w i t h the severe d r o u g h t s of 1934 and 1936 brought about a 50 p e r c e n t l o s s i n sagebrush f o l i a g e ( A r t i m e s i a t r i d e n t a t a ) . He found o n l y a 15 p e r c e n t l o s s of the same p l a n t a s h o r t d i s -t a n c e away where th e drought was the same but the g r a s s -hopper i n f e s t a t i o n was much l i g h t e r . The q u e s t i o n might be asked': "How can g r a s s h o p p e r damage be r e l a t e d t o o v e r g r a z i n g ? " Branson (22) has shown t h a t t h e r e i s a c o r r e l a t i o n between i n s e c t p o p u l a t i o n and c e r t a i n m o i s t u r e - t e m p e r a t u r e r e l a t i o n s . There i s an i n c r e a s e i n g r a s s h o p p e r s i n the. a r e a s t h a t are g r a z e d most h e a v i l y . The b e l i e f (7l) t h a t o v e r g r a z i n g alone by c a t t l e would not have r e s u l t e d i n the complete d e n u d a t i o n of g r a s s l a n d s and the subsequent l o s s of s o i l from wind and water e r o s i o n i s - 122 -r e p u d i a t e d by D i b b l e . F u r t h e r e x p e r i m e n t s (254) on normal and o v e r g r a z e d l a n d showed t h a t the t o t a l p o p u l a t i o n i n the o v e r -g r a z e d g r a s s l a n d i s on the average f o u r t i m e s as g r e a t as i n the normal p r a i r i e , r e s u l t i n g i n some cases i n permanent dam-age t o the g r a s s l a n d s and g r e a t i n j u r y t o food and s h e l t e r f o r i w i l d l i f e and c a t t l e as w e l l as t o s o i l improvement and e r o s i o n programmes (76). W h i l e s t u d y i n g h e a v i l y g r a z e d and o v e r g r a z e d a r e a s i n B r i t i s h Columbia (1947, 1947) as w e l l as i n A l b e r t a (1946) and Saskatchewan (1946, 1947), the w r i t e r found t h a t the numbers of grassh o p p e r s p r e s e n t i n t h o s e a r e a s f a r exceeded the numbers p r e s e n t on p r o p e r l y o r und e r g r a z e d a r e a s . Some of the a r e a s c o n s i d e r e d were i m m e d i a t e l y a d j a c e n t . I t may a l s o be shown t h a t w h i l e the i n i t i a l break i n the h a b i t a t i s due to ras h o v e r g r a z i n g r e s u l t i n g i n p a r t i a l de-n u d a t i o n and e r o s i o n , t h e s e f a c t o r s i n t u r n e x e r t an i n f l u e n c e on the g rasshopper p o p u l a t i o n which c o n t r i b u t e s t o f u r t h e r d e n u d a t i o n and e r o s i o n . Where t h i s e r o s i o n i s caused by wind the g r a s s h o p p e r ( A g e n c o t e t t i x deorum) has found a v e r y f a v o r a b l e environment. B a l l ' s study (10) of the g r a s s h o p p e r s of Colo r a d o and A r i z o n a i n d i c a t e s t h a t out o f about 130 s p e c i e s of t r u e g r a s s -hoppers o c c u r r i n g i n each s t a t e , o n l y about 5 or 6 s h o u l d be cased as i n j u r i o u s t o crops and s c a r c e l y more t h a n a dozen more s h o u l d be l i s t e d as of s e r i o u s i n j u r y to the g r a s s e s o f the range. This l e a v e s w e l l over 100 s p e c i e s t h a t are e i t h e r b e n e f i c i a l or of l i t t l e i mportance one way or the o t h e r . He - 123 -s t a t e s f u r t h e r t h a t many gr a s s h o p p e r s a re s t r i k i n g l y b e n e f i c i a l i n t h a t t h e y h e l p t o check the weeds t h a t would o v e r r u n t h e ranges. He f a i l s t o mention, however, t h a t the " s c a r c e l y more than a dozen s p e c i e s of gr a s s h o p p e r s I n j u r i o u s t o the range" r e a d i l y m u l t i p l y under f a v o r a b l e c o n d i t i o n s t o cause damages of the p r o p o r t i o n s shown i n Table IX as w e l l as cause consider-a b l e expense f o r c o n t r o l measures. B a l l a l s o f a i l s t o mention t h a t under p r o p e r range management, i.e., when o v e r g r a z i n g i s not p r e s e n t , the weed p o p u l a t i o n s are c o n t r o l l e d by the o t h e r s p e c i e s of the p l a n t a s s o c i a t i o n s w i t h o u t the a i d of the b e n e f i c i a l g r a s s h o p p e r s . TABLE IX Losses caused by Grasshoppers i n Montana (215). YEAR CULTIVATED CROPS RANGELAND TOTAL 1934 5,513,000 500,000 6,013,000 1935 2,434,000 600,000 • 3,034,000 1936 1,900.000 650.000 2.255.000 9,847,000 1,750,000 .11,597,000 These f i g u r e s a r e p r o b a b l y t o o low f o r the r a n g e l a n d s s i n c e t h e y a r e based on an e s t i m a t e d damage of a p p r o x i m a t e l y 16 t o 20 p e r c e n t of the range i n c e n t r a l and e a s t e r n Montana and a v a l u e of 10 c e n t s per a c r e of the g r a s s d e s t r o y e d . There i s a l s o the c o s t o f p o i s o n and c o n t r o l measures t o be c o n s i d e r e d . The Mormon c r i c k e t (Anabrus s i m p l e x ) , c o n t r a r y t o the • - 124 — g r a s s h o p p e r s p e c i e s , i s a g e n e r a l f e e d e r which i n plague p r o -p o r t i o n s o f t e n i n g e s t s a l l the v e g e t a t i o n p r e s e n t i n t h e path of i t s m i g r a t i o n . Swain (216) has found t h a t i t has an a f f i n i t y f o r the i n f l o r e s c e n c e s c a u s i n g g r e a t l o s s e s i n the r e p r o d u c t i v e powers of t h e p l a n t s . H i s o b s e r v a t i o n s of one-t e n t h a c r e p l o t s showed a l o s s i n f o r a g e p r o d u c t i o n v a r y i n g from l e s s than one p e r c e n t t o 100 p e r c e n t , w h i l e one p l o t l o s t 56 p e r c e n t of the t o t a l dry weight of the herbage, which i s e q u i v a l e n t to 483 pounds of f o r a g e . This;.amount - i s more f o r a g e than much of the s h o r t g r a s s p r a i r i e produces per y e a r i n i t s p r e s e n t g e n e r a l c o n d i t i o n . Smith (200) i n s t u d y i n g i n s e c t p o p u l a t i o n s on u n d e r g r a z e d , o v e r g r a z e d , and eroded l a n d s , found t h a t h a b i t a t c o n d i t i o n s i n s e v e r e l y o v e r g r a z e d a r e a s appear t o be v e r y u n f a v o r a b l e t o C h r y s o m e l i d s ( l e a f b e e t l e s ) but f a v o r a b l e to the M e l o i d a e ( b l i s t e r b e e t l e s ) . I n g e n e r a l the Hemiptera (bugs and l i c e ) i n c r e a s e both i n number of s p e c i e s and specimens under con-d i t i o n s produced by o v e r g r a z i n g but a r e not f a v o r e d by changes brought about by e r o s i o n f o l l o w i n g severe o v e r g r a z i n g . The Hemoptera ( c i c a d e s , t r e e h o p p e r s , e t c . ) showed b e h a v i o u r s i m i l a r to t h a t of the Hemiptera i n t h e i r r e a c t i o n to o v e r g r a z i n g but showed t h e i r g r e a t e s t abundance i n somewhat eroded a r e a s . I t i s e v i d e n t t h a t a g a i n the r e s u l t s of o v e r g r a z i n g do not t e r m i n a t e w i t h the s i m p l e l o s s of v e g e t a t i o n t o the g r a z i n g d o m e s t i c a t e d a n i m a l s , but some of the p o s s i b l y a v a i l a b l e f o r a g e i s a l s o consumed by i n s e c t s and o t h e r i n v e r t e b r a t e s , c a u s i n g heavy l o s s e s t o g r a z i e r s and crop p r o d u c e r s both t h r o u g h l o s s e s - 125 -i n p r o d u c t i o n and c o s t l y c o n t r o l measures. D. PREDATORS OF DOMESTIC GRAZING LIVESTOCK AND WILDLIFE A l t h o u g h p r e d a t o r s cause o n l y 1.5 t o 2 p e r c e n t of the annual l i v e s t o c k l o s s e s i n the w e s t e r n r a n g e l a n d s of t h e U n i t e d S t a t e s (164), the s p e c t a c u l a r n a t u r e of the l o s s has r e s u l t e d i n many p r e d a t o r y a n i m a l c o n t r o l programs. The es t a b l i s h m e n t of rewards and b o u n t i e s by many p r o v i n c e s , states, and stockmen's a s s o c i a t i o n s has r e s u l t e d i n c o n s i d e r a b l e hunt-i n g and t r a p p i n g by e x p e r i e n c e d h u n t e r s . ' The c o s t of thes e b o u n t i e s i s by no means a s m a l l f i n a n c i a l m a t t e r ( T a b l e X ) . The f o l l o w i n g t a b l e shows t h e b o u n t i e s p a i d by the B r i t i s h Columbia Game Commission a l o n e (25) • Table X Pr e d a t o r y Animal B o u n t i e s p a i d by the B r i t i s h Columbia Game Commission (1946). PREDATOR RATE BOUNTIES CLAIMED TOTAL Wolves $10/head 932 9,320.00 Cougars $15/head 461 6,915.00 Coyotes $ 5/head 239 1,195.00 Coyotes $ 2/head 2,481 4,962.00 TOTAL 1946 4,113 22,392.00 1922-46 673,658.80 ( l ) Coyotes The c o y o t e , a symbol of the ra n g e l a n d s of the N o r t h American West, i s c o n f i n e d i n i t s Canadian h a b i t a t to the t h r e e P r a i r i e P r o v i n c e s and B r i t i s h Columbia, where i t s range i s r e s t r i c t e d t o the t y p i c a l l y open or semi-wooded c o u n t r y . - 126 -C o n t r a r y t o most p r e d a t o r y a n i m a l s , the coyote p o p u l a t i o n s have d e c r e a s e d o n l y i n i s o l a t e d a r e a s where v i g o r o u s coyote e x t e r m i n a t i o n has "been u n d e r t a k e n . The g r e a t e s t l o s s e s i n -f l i c t e d by c o y o t e s are to t h e l i v e s t o c k i n d u s t r y , the s t o c k a f f e c t e d b e i n g m a i n l y sheep and p o u l t r y . Next t o the l o s s e s i n f l i c t e d upon domestic g r a z i n g a n i m a l s come tho s e upon game such as grouse, p h e a s a n t s , and ducks, as w e l l as d e e r . Although t h e r e are no r e c o r d s of o u t b r e a k s i n Canada, c o n s i d e r -able l o s s e s have been i n f l i c t e d on do m e s t i c a n i m a l s such as c a t t l e , h o r s e s , and dogs, t h r o u g h the spread of r a b i e s from coyotes ( 6 3 ) . The i n t r o d u c t i o n of d o m e s t i c a t e d g r a z i n g animaJs has p r o v i d e d a new source of food s u p p l y f o r the co y o t e which may enable i t t o s u r v i v e when i t s normal d i e t f a l l s s h o r t . C r i d d l e (63) c o n s i d e r s t h a t the s h e e p - k i l l i n g h a b i t i s by no means a u s u a l one; b e i n g more t h e work of one or two o l d coyotes i t i s a l s o p r o b a b l e t h a t most of t h e damage i s done by the l a r g e common coyote ( C a n i s l a t r a n s ) e a s t of the Rocky Moun-t a i n s and the almost e q u a l l y . l a r g e mountain coyote ( C a n i s  l i s t i s ) west of them. In B r i t i s h Columbia, the mountain coyote shows a g r e a t e r l i k i n g f o r sheep than the common coyote, r e s u l t i n g i n a r t i c l e s by such men as Major A l l a n B r o o k s , the noted n a t u r a l i s t , and T.P. MacKenzie, f o r m e r P r o v i n c i a l Com-m i s s i o n e r of G r a z i n g , each condemning the c o y o t e . On the o t h e r hand, not a l l the a c t i v i t i e s of the coyote are d e t r i m e n t a l . I t i s u s e f u l b o t h as a. d e s t r o y e r of n o x i o u s r o d e n t s and s m a l l range a n i m a l s and as a f u r p r o d u c e r . A t t e n t i o n has been drawn to the damage t h a t may r e s u l t from - 127 -• the a c t i v i t i e s of the a n i m a l s and i n s e c t s t h a t comprise the coyote d i e t . These i t e m s of d i e t may i n c l u d e r a b b i t s , gophers, mice, b i r d s , f r o g s , g r a s s h o p p e r s , w h i t e g r u b s , as w e l l as t h e more p u b l i c i z e d s p e c i e s such as c a l v e s , sheep and deer. Coyotes (80) on a 4,600 acre f o o t h i l l range i n C a l i f o r n i a were found to f e e d m a i n l y on c o t t o n t a i l r a b b i t s and ground s q u i r r e l s . They comprise 45«4 and 31»2 p e r c e n t of the d i e t r e s p e c t i v e l y . These f a c t s i n d i c a t e how d i f f i c u l t i t • i s t o a r r i v e at an a c c u r a t e c o n c l u s i o n as to the c o y o t e ' s s t a n d i n g . At one time i t does i n f i n i t e harm, a t a n o t h e r i t s b e n e f i t s p r o b a b l y outweigh i t s h a r m f u l a c t i v i t i e s . The evidence a g a i n s t the coyote r e l a t e s t o i t s d e s t r u c -t i o n of sheep, o c c a s i o n a l c a l v e s , and p o u l t r y . There a r e , however, y e a r s when due to r a b b i t s c a r c i t y the l o s s e s t o l i v e s t o c k w i l l be g r e a t . T h i s problem can be overcome i n most areas by s t u d y i n g the p r e v a l e n c e of w i l d r a b b i t s and r o d e n t s and the n e c e s s a r y p r e c a u t i o n s t a k e n a c c o r d i n g l y . I t i s e v i d e n t i n a r e a s of o v e r g r a z i n g where the r o d e n t and r a b b i t p o p u l a t i o n n o r m a l l y i n c r e a s e s t h a t the presence o f the coyote i s an a i d toward p r o t e c t i n g the g r a s s l a n d s from r a b b i t and r o d e n t i n f e s t a t i o n , thus a i d i n g the r e g r a s s i n g p r o c e s s e s . In t h e s e a r e a s the presence of a c o n s c i e n t i o u s h e r d e r , e s p e c i -a l l y j u s t a t dawn, w i l l have a marked i n f l u e n c e i n r e d u c i n g sheep l o s s e s from c o y o t e s . Another e x p e n s i v e but u s e f u l p r o -t e c t i o n i s the c o y o t e - p r o o f f e n c e . The c r a v i n g f o r lamb and mutton as w e l l as v e n i s o n , how-e v e r , has made the c o n t i n u e d e x i s t e n c e of the mountain coyote - 128 -of B r i t i s h Columbia much l e s s d e s i r a b l e i f sheep p r o d u c t i o n i s t o become a permanent s u c c e s s . I n g e n e r a l , the a d m i n i s t r a t i o n and s u p e r v i s i o n of r o d e n t and p r e d a t o r y a n i m a l c o n t r o l s h o u l d be of t h e most r i g o r o u s k i n d so as t o r e s t r i c t the k i l l i n g of d e t r i m e n t a l s p e c i e s to the p a r t i c u l a r a r e a s where t h e y a r e c l e a r l y d e s t r u c t i v e , and even i n such a r e a s t o reduce them t o the r e q u i s i t e • p o i n t . The c o n t r o l s h o u l d be l o c a l and s p e c i f i c , not g e n e r a l and u n i v e - r s a l , and s h o u l d be d e c i d e d upon o n l y a f t e r c a r e f u l i n v e s t i g a t i o n . (2) Wolves I t i s w e l l known t h a t wolves d e s t r o y l a r g e numbers of de"er and s i m i l a r a n i m a l s w h i c h a r e p a r t of t h e i r n a t u r a l d i e t . As i n the case of c o y o t e s , the i n t r o d u c t i o n of domestic g r a z i n g a n i m a l s has p r o v i d e d o t h e r prey which wolves t a k e ad-vantage o f . Sheep p r o b a b l y s u f f e r most, but young h o r s e s and c a t t l e are o f t e n d e s t r o y e d by them (63). The v a l u e of wolves l i e s c h i e f l y i n t h e i r p e l t s and as d e s t r o y e r s of n o x i o u s r o d e n t s and s m a l l mammals. Dr. Cowan (58) i n s t u d y i n g t i m b e r wolves i n the Rocky Mountain N a t i o n a l Park of Canada f o u n d t h a t 18 p e r c e n t of the a n n u a l d i e t of wolves i s r o d e n t s . They a l s o p l a y "a u s e f u l p a r t i n e l i m i n a t i n g s i c k l y game an i m a l s due to the f a c t t h a t the weakly are more apt t o f a l l p r e y t o them t h a n are h e a l t h y a n i m a l s . Men of the Waldo Stockmen's A s s o c i a t i o n have s t a t e d t h a t wolves and c o y o t e s a r e among the stockmen's b e s t f r i e n d s . The r e a s o n f o r t h i s i s t h a t they h e l p keep down the numbers of deer and game - 129 -t h a t m i g r a t e from the N a t i o n a l Parks t o the ra n c h h a y s t a c k s d u r i n g t i m e s of f e e d s h o r t a g e s . These stockmen, however, are engaged i n c a t t l e , not sheep, p r o d u c t i o n . Consid e r i n g the i n f o r m a t i o n c o n c e r n i n g the w o l f , i t would appear t h a t i n s p i t e of i t s l i m i t e d b e n e f i t s i t i s f a r more d e t r i m e n t a l and f a r t o o dangerous t o t o l e r a t e i n g r a z i n g d i s t r i c t s . (3) Other P r e d a t o r s Among the o t h e r p r e d a t o r s known t o c o n t r i b u t e t o l i v e -s tock l o s s e s are the mountain l i o n or cougar, the g r i z z l y , b l a c k and cinamon b e a r s , and the bobcat or l y n x . However, t h e r e i s no evidence i n the l i t e r a t u r e t h a t t h e s e s p e c i e s i n c r e a s e i n abundance as a r e s u l t of o v e r g r a z i n g , and hence t h e y w i l l not be d i s c u s s e d . Much has been w r i t t e n c o n c e r n i n g the e f f e c t t h a t p r e -d a t o r y mammals have on the r i s e and f a l l i n abundance of v a r i o u s r o d e n t s p e c i e s . I t has been condended ( 5 7 ) t h a t the p e r s i s t e n t w a r f a r e on c o y o t e s , b o b c a t s , w o l v e s , w e a s e l s and o t h e r p r e d a t o r y f u r b e a r i n g a n i m a l s i s r e s p o n s i b l e f o r the e x c e s s i v e abundance a t t i m e s of j a c k r a b b i t s , f i e l d mice, ground s q u i r r e l s , marmots, pocket gophers and oth e r s m a l l mammals r e p u t e d t o be agents of o v e r g r a z i n g . Couch s t a t e s t h a t w h i l e t h e r e i s no doubt t h a t p r e d a t o r y mammals are a f a c t o r i n c o n t r o l l i n g r o d e n t s , y e t t h e y p l a y a s m a l l p a r t i n m a i n t a i n i n g the b a l a n c e . Large f a c t o r s a r e i n v o l v e d and t h e s e i n c l u d e s e a s o n a l c o h d i t i o n s , f e c u n d i t y v o f - 130 -the s p e c i e s , the a c t s of man i n p r o v i d i n g abundant f o o d , and the presence of n a t u r a l and o t h e r s h e l t e r . On the o t h e r hand, ro d e n t s the s i z e of ground s q u i r r e l s or s m a l l e r are more e f f e c t i v e l y d e c r e a s e d i n numbers by r a p t o r i a l b i r d s t h a n by p r e d a t o r y a n i m a l s . Couch b e l i e v e s t h a t t h e v a l u e of p r e d a -t o r y a n i m a l s i n c o n t r o l l i n g i n j u r i o u s r o d e n t s has been o v e r -e s t i m a t e d . P r e s n a l l ( s work (l6k) adds weight t o t h i s argument s i n c e he found t h a t heavy rodent p o p u l a t i o n c y c l e s a re un-r e l a t e d t o p r e d a t o r f l u c t u a t i o n s . I f t h e s e r e p o r t s a re v e r i f i e d i t may r e s u l t t h a t the complete b i o l o g i c a l c o n t r o l of r o d e n t s (187) on o v e r g r a z e d l a n d can be c a r r i e d out by r a p t o r i a l b i r d s and hence the stockmen w i l l be f r e e t o e l i m i n a t e the d e t r i m e n t a l e f f e c t s of the f u r b e a r i n g p r e d a t o r s w h i l e t h e s e b i r d s assume the b e n e f i c i a l work f o r m e r l y c a r r i e d on by t h e s e a n i m a l s . - 131 -VI. DISCUSSION m F,or over h a l f a c e n t u r y p e r i o d i c c o m p l a i n t s have been made r e g a r d i n g o v e r g r a z i n g i n the West and i t s abuses. These c o m p l a i n t s and demands f o r c o r r e c t i v e measures r e s u l t e d i n the e s t a b l i s h m e n t of the P.F.R.A. i n Canada and the Conserva-t i o n s e r v i c e s i n the U n i t e d S t a t e s . Through t h e s e b o d i e s a c o n c e r t e d e f f o r t has been made t o stem the d e s t r u c t i o n and economic l o s s caused by o v e r g r a z i n g . The q u e s t i o n a r i s e s : "Why and how d i d o v e r g r a z i n g become such a problem t h a t t h e l e g i s l a t u r e s of Canada and the U n i t e d S t a t e s were f o r c e d t o a p p r o p r i a t e l a r g e sums of money i n an attempt to r e s t o r e the p r o d u c t i v e and p r o t e c t i v e v a l u e s of the r a n g e l a n d s of t h e West?" The t e x t i n d i c a t e s t h a t one of the reasons n e c e s s i t a t i n g such e x p e n d i t u r e s has been t h e l a c k of knowledge and under-s t a n d i n g of the p r i n c i p l e s of range management. In t h e pa s t many r a n c h e r s knew n o t h i n g of how t o m a i n t a i n s e m i - a r i d r a n g e s , t o r e s t o r e d e p l e t e d r a n g e s , t o p l a n g r a z i n g systems and t o prepare f o r or prev e n t p e r i o d s of drought and f e e d s h o r t a g e . The d e p l e t i o n of range f o r a g e , as i n d i c a t e d i n the i n t r o d u c t i o n , became of c o n s i d e r a b l e concern p r i o r t o t h e t u r n of the c e n t u r y . The a d d i t i o n of sheep to ranges a l r e a d y s t o c k e d t o c a p a c i t y w i t h c a t t l e , c o u p l e d w i t h the f a c t t h a t - 132 -s e t t l e m e n t and c u l t i v a t i o n was e l i m i n a t i n g much of t h e highly-p r o d u c t i v e p o r t i o n s of the range, r e s u l t e d i n an i n t e n s i f i e d use of the r e m a i n i n g r a n g e l a n d s . This i n t e n s i f i e d use had but one r e s u l t -- o v e r g r a z i n g . W h i l e the e f f e c t s of c l i m a t e on g r a z i n g p r o cedures have not been d i s c u s s e d , droughts do p l a y a p*art i n e n c o u r a g i n g o v e r g r a z i n g . Ranchers have c o n t i n u a l l y a t t e m p t e d t o graze ranges w i t h o u t r e l a t i n g l i v e s t o c k numbers t o c a r r y i n g c a p a c i t y or on t h e b a s i s of t h e f o r a g e produced d u r i n g p e r i o d s of good growth. A g a i n o v e r g r a z i n g i s t h e i n e v i t a b l e r e s u l t d u r i n g p e r i o d s of drought such as the mid 1930's. F l u c t u a t i o n s i n l i v e s t o c k p r i c e s have a l s o p l a y e d an i m p o r t a n t r o l e i n c a u s i n g o v e r g r a z i n g . Stockmen who bought b r e e d i n g herds a t h i g h p r i c e s d u r i n g the peak, of a boom p e r i o d i n v a r i a b l y g r a z e more i n t e n s e l y i n an attempt t o r e a l i z e a p r o f i t on a d e c l i n i n g market. The l a c k of a c o n s t r u c t i v e n a t i o n a l l a n d p o l i c y ( i n both the U n i t e d S t a t e s and Canada) a p p l i c a b l e t o the s e m i - a r i d and mountain g r a z i n g l a n d s of the West has been a n o t h e r major f a c t o r i n o v e r g r a z i n g . The f a i l u r e t o c l a s s i f y g r a z i n g a r e a s a c c o r d i n g t o t h e i r a c t u a l l o n g - t e r m p r o d u c t i v e c a p a c i t y -- as i n d i c a t e d i n S e c t i o n I I - has a l s o p l a y e d an i m p o r t a n t r o l e i n f o r a g e d e p l e t i o n . Today, as p r e v i o u s l y d i s c u s s e d i n the body of t h i s T h e s i s , the western, range a r e a s c o n s t i t u t e r e g i o n s which are c o m m e r c i a l l y s u i t e d o n l y f o r g r a z i n g l i v e s t o c k because of one or more adverse a g r i c u l t u r a l c o n d i t i o n s such as: - 1 3 3 -(a) rough topography; (b) low p r e c i p i t a t i o n , or t h e l a c k of f a c i l i t i e s t o d e v e l o p i r r i g a t i o n , or adverse c l i m a t i c c o n d i t i o n s . As i n d i c a t e d i n S e c t i o n IV, the demands made on n a t i v e v e g e t a t i o n i n range a r e a s s u r p a s s t h a t of s u p p l y i n g f e e d f o r g r a z i n g l i v e s t o c k . The p r e s e r v a t i o n of a s a t i s f a c t o r y w a t e r -shed c o n d i t i o n on r a n g e l a n d s i s v i t a l t o t h e w e l l b e i n g o f the West. I r r i g a t i o n , h y d r o e l e c t r i c and m u n i c i p a l water s u p p l y e n t e r p r i s e s depend on a s t a b l e f l o w from water y i e l d -i n g r a n g e s . Water power i s m a i n t a i n e d by stream f l o w from range w a t e r s h e d s . I t i s of g r e a t importance to m a i n t a i n an unbroken v e g e t a t i o n and a p r o d u c t i v e s o i l on a l l r a n g e l a n d s and the optimum y i e l d of water from range w a t e r s h e d s . De-p l e t i o n of the v e g e t a t i o n , as p r e v i o u s l y shown, has r e s u l t e d i n f l o o d s and e r o s i o n , menacing the s o c i a l and economic s e c u r i t y of the e n t i r e c o n t i n e n t . The d e s t r u c t i o n of s o i l and t h e impairment of watershed v a l u e s i s w i t h o u t doubt one of the g r a v e s t r e s u l t s from misuse of t h e range. . In B r i t i s h Columbia, as e l s e w h e r e , f a c t o r s such as w i l d l i f e , f o r e s t r y and r e c r e a t i o n are of v a l u e and i n t e r e s t t o much of the- p o p u l a t i o n . As i n d i c a t e d i n the t e x t , t h e s e f a c t o r s must a l s o be c o n s i d e r e d i n d e t e r m i n i n g a range p o l i c y or management program. How can the p r o d u c t i v i t y and v a l u e of t h e w e s t e r n g r a z i n g r e g i o n s be m a i n t a i n e d ? The answer l i e s i n the a p p l i -c a t i o n and s t r i c t adherence t o t h e p r i n c i p l e s of sound range management. Management of west e r n r a n g e s . w i t h t h e i r i n t r i -- 134 -c a t e and v a r i a b l e p a t t e r n of c o n d i t i o n s and t h e i r i n t e r -l o c k i n g p r i v a t e and p u b l i c v a l u e s i s not an easy j o b . I t has to do w i t h d e t e r m i n i n g t h e p r o p e r g r a z i n g system, g r a z i n g c a p a c i t y , season of use,, c l a s s of l i v e s t o c k , r e s e e d i n g p r a c -t i c e s , game management program, and a l l r e l a t e d a c t i v i t i e s n e c e s s a r y t o a t t a i n the h i g h e s t use c o n s i s t e n t w i t h t h e p r o t e c t i v e and s u s t a i n e d y i e l d of a l l t h e r e s o u r c e s . C o n s e r v a t i o n and p r o t e c t i o n of t h e g r a z i n g r e s o u r c e s of B r i t i s h Columbia and elsewhere may be a c h i e v e d w i t h l i t t l e s k i l l or e f f i c i e n c y s i m p l y by r e s t r i c t i n g use. To do so, however, would r e s u l t i n unemployment f o r a c o n s i d e r a b l e p o r t i o n of t h e p o p u l a t i o n . The most e f f i c i e n t method i s . t o a p p l y the knowledge.and s k i l l which w i l l r e s u l t i n the h i g h e s t y i e l d of r e s o u r c e s c o n s i s t e n t w i t h t h e i r p e r p e t u a t i o n . An a p p r a i s a l of e i t h e r the r e s o u r c e of i t s d e p l e t i o n i s p o s s i b l e o n l y i n terms of t h e i r s o c i a l and economic s i g n i f i -cance. The p r o d u c t i o n of l i v e s t o c k , the water y i e l d , and the income, p l e a s u r e , and d i v e r s i o n from the w i l d l i f e and r e c r e a t i o n a l o p p o r t u n i t i e s dependent on g r a z i n g l a n d s mean: n o t h i n g u n l e s s t h e y add t o a n a t i o n ' s w e l f a r e . On t h e o t h e r hand, a reduced g r a z i n g c a p a c i t y , e r o s i o n , f l o o d s , dust s t o r m s , d e p l e t i o n of w i l d l i f e p o p u l a t i o n s , and the i n h i b i t i o n of r e c r e a t i o n c a r r y no import u n l e s s t h e y d e t r a c t f rom t h e n a t i o n ' s w e l f a r e . The q u e s t i o n a r i s e s : "Are the e f f e c t s of o v e r g r a z i n g i n i n t e r i o r B r i t i s h Columbia as d r a s t i c as tho s e found i n o t h e r areas throughout the w e s t e r n g r a z i n g r e g i o n s ? " I n a n s w e r i n g - 135 -such a q u e s t i o n , many f a c t o r s must be weighed and c o n s i d e r e d . Areas such as I n d i a n r e s e r v e s , r o a d s i d e s , c a t t l e t r a i l s and h o l d i n g grounds have been as s e r i o u s l y abused as any o t h e r g r a z i n g areas i n t h e west. However, B r i t i s h Columbian range-l a n d s , i n g e n e r a l , have s u f f e r e d t o a l e s s e r degree t h a n average f o r one or more of t h e f o l l o w i n g r e a s o n s . (1) Because g r e a t e r r e t u r n s c o u l d be made on i n v e s t -ments i n l u m b e r i n g , m i h i n g and o t h e r more i n t e n s i v e forms of a g r i c u l t u r e , the e a r l y com-p e t i t i o n f o r g r a z i n g l a n d s was not as i n t e n s e as i t was i n o t h e r areas t h r o u g h o u t the West. (2) The topography of t h e r a n g e l a n d and t h e n a t u r a l v e r t i c a l z o n a t i o n of the v e g e t a t i o n p e r m i t s a n a t u r a l form of r o t a t i o n a l g r a z i n g . The s t o c k w i n t e r i n t h e v a l l e y bottoms and as p l a n t growth advances, t h e y g r a d u a l l y g r a z e up and onto the h i g h e r g r a z i n g r e g i o n s . (3) The n a t u r e of t h e topography and the v e g e t a t i o n tends t o d i v i d e the r a n g e l a n d s i n t o n a t u r a l g r a z i n g u n i t s , many of which a re i n d i v i d u a l l y owned and c o n t r o l l e d . (4) Long w i n t e r f e e d i n g p e r i o d s , rough t o p o g r a p h y , s h i p p i n g and t r a i l i n g d i f f i c u l t i e s , p r e d a t o r y a n i m a l s , and o t h e r e n v i r o n m e n t a l f a c t o r s masked the t r u e v a l u e of the i n t e r i o r r a n g e l a n d s and d i s c o u r a g e d i n t e n s i v e l i v e s t o c k p r o d u c t i o n f o r many y e a r s . (5) There was and i s now a s h o r t a g e of hayla n d s and w i n t e r f e e d i n g grounds. (6) The c l i m a t e of B r i t i s h Columbia i s not s u b j e c t t o the p e r i o d i c f l u c t u a t i o n s found i n many of the g r a z i n g r e g i o n s . (7) R a i n f a l l i n t e n s i t y i s c o n s i d e r a b l y l e s s t h a n t h a t found i n most g r a z i n g r e g i o n s . W h i l e g r a z i n g has not been as se v e r e i n B r i t i s h Columbia as i n many o t h e r a r e a s , i t has c e r t a i n l y not been n e g l i g i b l e - 136 -or a b s e n t , nor has the i n t e r i o r been spared t h e d i s t u r b a n c e s i n t h e b i o t i c community which are a s s o c i a t e d w i t h o v e r g r a z i n g . The d e t e r i o r a t i o n and abuse of s p r i n g - f a l l range i s almost u n i v e r s a l throughout the West, and B r i t i s h Columbia i s no e x c e p t i o n . Nor i s t h e r e any i n d i c a t i o n t h a t t h e e x t e n t or c a r r y i n g c a p a c i t y of t h i s type o f range w i l l be markedly i n -c r e a s e d . The major expense i n p r o d u c i n g range l i v e s t o c k i s w i n t e r i n g and emergency f e e d i n g . I t i s o n l y n a t u r a l , t h e n , f o r the producer t o attempt to t u r n out h i s herd as soon as new growth b e g i n s i n the s p r i n g . Granted, he saves on t h e c o s t of w i n t e r i n g under t h i s system, but he does not g i v e the v e g e t a t i o n a chance t o become e s t a b l i s h e d , t o r e p l e n i s h r o o t r e s e r v e s , or t h e ground a chance t o d r y . Under such c o n d i -t i o n s , the v i g o r of t h e p l a n t s on s p r i n g range i s weakened. These ranges r e c e i v e f u r t h e r abuse i n t h a t when r a n c h e r s round up f a t s t o c k f o r t h e l a t e June market and f i n d t h a t the market i s poor or t h e s h i p p i n g date d e l a y e d , t h e y l e a v e t h e s e a n i m a l s on t h e lower g r a s s l a n d s ( s p r i n g - f a l l range) u n t i l t h ey can be s h i p p e d . D u r i n g t h i s p e r i o d the f a t s t o c k are a b l e to g r a z e a h i g h p e r c e n t a g e of t h e seed culms or a g a i n reduce the v i g o r of the p l a n t s t o such a degree t h a t p l a n t r e p r o d u c t i o n i s h i n d e r e d or d e l a y e d . W i t h t h e f u r t h e r e x p a n s i o n of i r r i g a t i o n , more of t h e s p r i n g - f a l l range w i l l be l o s t , r e s u l t i n g i n a f u r t h e r i n t e n s i f i c a t i o n of i t s use. Lower g r a s s l a n d s are not t h e o n l y v e g e t a t i o n a l zone t o s u f f e r o v e r g r a z i n g , but as e x t r e m i t i e s of t h e range, such as the f o r e s t zones, are approached, the d e l e t e r i o u s e f f e c t s - 137 -l e s s e n . The use of f o r e s t e d ranges f o r summer g r a z i n g has removed some of the g r a z i n g p r e s s u r e . U n t i l r e c e n t y e a r s , many r a n c h e r s c o u l d not be c o n v i n c e d t h a t l i v e s t o c k a r e a b l e to make e c o n o m i c a l g a i n s from open c o n i f e r o u s f o r e s t range d u r i n g t h e summer and e a r l y f a l l . The adverse r a t i o of s p r i n g - f a l l range to summer f o r e s t range i s one of the b a s i c causes f o r the l a c k of f u l l u t i l i z a t i o n of f o r e s t range. Many o t h e r f a c t o r s may be i n t r o d u c e d t o i n c r e a s e the p r o -d u c t i v i t y of B r i t i s h Columbia r a n g e l a n d s . Reseeding d e p l e t e d ranges t o s p e c i e s such as c r e s t e d wheatgrass can do much toward i n c r e a s i n g the c a r r y i n g c a p a c i t y of t h e s e r a n g e s . Management p r a c t i c e s such as f e n c i n g and r i d i n g , s a l t i n g and water* development, to c o n t r o l l i v e s t o c k movements w i l l a s s u r e optimum u t i l i z a t i o n of the range f o r a g e . The c o n t r o l of p a r a s i t e s such as f l i e s and t i c k s and t h e use of w e l l b r e d s t o c k t h a t can make econo m i c a l g a i n s w i l l a l s o do much toward d e r i v i n g the maximum r e t u r n s from a range. W i t h t h e e x c e p t i o n of t h e C h i l c o t i n and upper Windermere V a l l e y s , the v e g e t a t i o n of range a r e a s throughout B r i t i s h Columbia i s i m p r o v i n g . This i s due t o the combined e f f e c t s of improved management, l i v e s t o c k , and g r a z i n g p r a c t i c e s , t h e i n c r e a s e d use of f o r e s t range, b e t t e r growth c o n d i t i o n s , i n c r e a s e d a c t i v i t i e s and e f f i c i e n c y of t h e G r a z i n g D i v i s i o n of the B.C. F o r e s t S e r v i c e , h i g h l i v e s t o c k p r i c e s and freedom from g r a s s h o p p e r o u t b r e a k s . The causes of o v e r g r a z i n g i n t h e C h i l c o t i n V a l l e y are b e i n g removed, by the a c t i v i t i e s o f the F o r e s t S e r v i c e , w h i l e the Dominion E x p e r i m e n t a l Farm S e r v i c e - 138 -i s c o n d u c t i n g r e s e e d i n g e x p e r i m e n t s . The s i t u a t i o n i n t h e Windermere V a l l e y has a r i s e n l a r g e l y t h r o u g h t h e n e g l e c t of th e r a n c h e r s . They have p e r m i t t e d h o r s e s t o r u n w i l d , and c o n s e q u e n t l y the horse p o p u l a t i o n has i n c r e a s e d t r e m e n d o u s l y . /The F o r e s t S e r v i c e i s p l a n n i n g t o r e s t r i c t the number of horses i n t h i s a r e a d u r i n g 1949. W h i l e o t h e r a r e a s throughout the West have s u f f e r e d ex-c e s s i v e water and sheet e r o s i o n , t h e r e i s v e r y l i t t l e e v i d e n c e of h a r m f u l s o i l l o s s throughout t h e ranges of i n t e r i o r B r i t i s h Columbia. There a r e some i n d i c a t i o n s of e r o s i o n a l o n g r o a d -s i d e s and on k n o l l s , e s p e c i a l l y i n the Thompson and N i c o l a V a l l e y s , but t h e s e are not c o n s i d e r e d s e r i o u s . In t h i s r e s p e c t , much c r e d i t i s due t o the annual g r a s s downy brome or c h e a t g r a s s . This p l a n t i n v a d e s o v e r g r a z e d r e g i o n s , l e a v i n g the s o i l w e l l c o v e r e d and c l o s e l y bound. Other reasons f o r the l a c k of s o i l e r o s i o n have been d i s c u s s e d . To what degree o v e r g r a z i n g has i n c r e a s e d t h e speed of r u n - o f f and reduced t h e water h o l d i n g c a p a c i t y of the r a n g e l a n d s of t h i s p r o v i n c e has not y e t been d e t e r m i n e d . During the 1930's and e a r l y 1940's, outb r e a k s of g r a s s -hoppers caused some a l a r m among t h e ranches of the N i c o l a , C h i l c o t i n , S imilkameen, Thompson and Okanagan V a l l e y s . How-eve r , t h e combined e f f e c t s of good growing c o n d i t i o n s , good l i v e s t o c k . p r i c e s , and sound management p r a c t i c e s has reduced the extent of many of the g r a s s h o p p e r b r e e d i n g grounds. At one t i m e , some of the Douglas Lake C a t t l e Company ranges were n o t o r i o u s l y o v e r g r a z e d and n o t e d to be some of t h e most - 139 -prominent b r e e d i n g grounds of g r a s s h o p p e r s i n the N i c o l a V a l l e y . Under the a s t u t e management of Mr. B.K.DeP. Chance, the d e p l e t i o n of t h e s e ranges has ceased and a marked improve-ment i n t h e v e g e t a t i o n may be seen. At p r e s e n t the N i c o l a I n d i a n Reserve i s one of the few gra s s h o p p e r a r e a s i n the N i c o l a t h a t has not shown improvement. Mr. B u c k e l l , Dominion E n t o m o l o g i s t , Kamloops, B.C., now c o n s i d e r s t h a t the g r e a t e s t grasshopper danger areas a r e i n t h e C h i l c o t i n V a l l e y . S m a l l mammals have never been as g r e a t a problem i n B r i t i s h Columbia as i n o t h e r a r e a s of the West. Th i s i s p r o -b a b l y due to t h e p r e v a l e n c e of p r e d a t o r s . The o n l y a r e a t h a t has s u f f e r e d t o any g r e a t e x t e n t has been t h a t p o r t i o n of t h e N i c o l a V a l l e y near Stump Lake. At one t i m e t h e r e was a f a i r l y h i g h c o n c e n t r a t i o n of ground s q u i r r e l s i n t h i s a r e a , but t o d a y they are v i r t u a l l y a bsent. In f a c t , many of t h e s i g n s of rodent h a b i t a t i o n , such as burrows and e a r t h e n hummocks, have d i s a p p e a r e d . Many of the r a n c h e r s i n t h i s a r e a c l a i m t h a t the removal of the coyote bounty and the subsequent r e t u r n of t h i s p r e d a t o r caused t h i s r e d u c t i o n i n ground s q u i r r e l numbers. Dr. Cowan b e l i e v e s t h a t r e p o r t s of the c o n t r o l of h i b e r n a t i n g a n i m a l s such as ground s q u i r r e l s by p r e d a t o r s must be c a r e f u l l y weighed and c o n s i d e r e d . Undoubtedly, t h e improvement i n n a t i v e v e g e t a t i o n p l a y e d some p a r t s i n c e t h i s a n i m a l , as p r e v i o u s l y i n d i c a t e d , p r e f e r s a s s o c i a t i o n s l o w e r i n t h e v e g e t a t i o n a l s u c c e s s i o n . The e f f e c t s of p r e d a t o r y a n i m a l s such as wol v e s , b e a r s , and c o u g a r s , are more s t r o n g l y f e l t i n B r i t i s h Columbia t h a n - 140 -i n most range a r e a s . However, i t i s t h e water's b e l i e f t h a t t h i s p r e d a t i o n i s not the r e s u l t of o v e r g r a z i n g but r a t h e r t h a t l a r g e expanses of u n i n h a b i t e d l a n d a re p r e v a l e n t t h r o u g h -out the p r o v i n c e . In the U n i t e d S t a t e s , c o n s e r v a t i o n i s t s a re g r a v e l y con-cerned w i t h the w i l d l i f e s i t u a t i o n , e s p e c i a l l y t h a t of t h e deer, e l k and o t h e r b i g game species.. Throughout much of t h e range r e g i o n s of t h e U n i t e d S t a t e s t h e r e are few areas tha-t are u n s u i t e d f o r domestic l i v e s t o c k p r o d u c t i o n , and conse-q u e n t l y t h e r e i s l i t t l e range l e f t f o r w i l d l i f e . I f t h e ranges a r e o v e r g r a z e d , t h e r e i s not enough f e e d l e f t f o r w i l d l i f e , and s t a r v a t i o n i s t h e i n e v i t a b l e r e s u l t . I n B r i t i s h Columbia, on the o t h e r hand, the s i t u a t i o n i s r e v e r s e d . There i s r e l a t i v e l y l i t t l e range s u i t a b l e f o r domestic l i v e s t o c k p r o d u c t i o n w h i l e w i t h the, p o s s i b l e e x c e p t i o n of w i n t e r f e e d i n g grounds the w i l d l i f e s p e c i e s have v i r t u a l l y the same range t h e y always had. U n f o r t u n a t e l y , o v e r g r a z i n g has caused c o n s i d e r a b l e h a r d -s h i p s f o r game b i r d s , e s p e c i a l l y ducks. Many of the l a k e s , swamps, and ponds on i n t e r i o r r a n g e l a n d s s e r v e as r e s t i n g p l a c e s and b r e e d i n g grounds f o r m i g r a t o r y ducks. Many o f t h e swamps have been d r a i n e d and used f o r the p r o d u c t i o n of w i l d or swamp hay which i s a so u r c e of w i n t e r f e e d f o r l i v e s t o c k . Und e r c o n d i t i o n s of o v e r g r a z i n g , l i v e s t o c k c r o p the v e g e t a t i o n around the shores and edges of many of t h e s e l a k e s and ponds t o such a degree t h a t no v e g e t a t i o n and hence no p r o t e c t i v e cover i s l e f t f o r the n e s t i n g b i r d s . Dr. Cowan sug g e s t s t h a t - 141 -a p o r t i o n of t h e shore l i n e of these ponds and l a k e s s h o u l d be f e n c e d o f f t o a l l o w t h e ducks an o p p o r t u n i t y <to n e s t . I n summary, i t i s c l e a r t h a t t h e r a n g e l a n d s of B r i t i s h Columbia are i m p r o v i n g and many of the d e l e t e r i o u s p r a c t i c e s t h a t have c o n t r i b u t e d to o v e r g r a z i n g i n t h e past a r e b e i n g e l i m i n a t e d . However, care must be t a k e n so t h a t the c o n d i t i o n s of o v e r g r a z i n g t h a t became so p r e v a l e n t t h r o u g h o u t the e n t i r e West a r e never p e r m i t t e d t o occur a g a i n i n B r i t i s h Columbia. - 142 — V I I . SUMMARY AND CONCLUSIONS (1) Present range r e g i o n s , i n B r i t i s h Columbia and the West, have r e s u l t e d from i n t e r a c t i o n s of edaphic and b i o t i c f a c t o r s . (2) Rangelands of B r i t i s h Columbia comprise a s m a l l p o r -t i o n of the a r e a of t h i s p r o v i n c e ; the g r a z i n g r e g i o n s r e p r e -s e n t e d are the bunchgrass and c o n i f e r o u s f o r e s t r e g i o n s . (3) A n . a p p r a i s a l of t h e g r a z i n g h i s t o r y of the West l e a d s t o an u n d e r s t a n d i n g of p r e s e n t range c o n d i t i o n s . (4) A v e g e t a t i v e c o v e r i s of prime importance i n the maintenance of the West. R e a l i z a t i o n of t h i s was g e n e r a l l y l a t e i n coming. E x t e n s i o n and range s u r v e y s have done much toward o b v i a t i n g the p r o t e c t i v e and p r o d u c t i v e v a l u e of such c o v e r . (5) C l a s s i f i c a t i o n of v e g e t a t i o n p r o v i d e s a b a s i s f o r d e t e r m i n i n g the i n t e n s i t y of range use and f u t u r e range management p r a c t i c e s . (6) I n B r i t i s h Columbia, as e l s e w h e r e , range e n t e r p r i s e s are dependent upon l i v e s t o c k p r o d u c t s p r o d u c t i o n per a c r e r a t h e r than l i v e s t o c k numbers. - 143 -(7) With o v e r g r a z i n g , calf and lamb c r o p s , wool produc-t i o n , and meat p r o d u c t i o n d e c r e a s e , w h i l e death and f o r a g e wastages i n c r e a s e . (8) Removal of the v e g e t a t i v e cover by o v e r g r a z i n g causes s e r i o u s l o s s e s through wind and water e r o s i o n . A l -though i n B r i t i s h Columbia l e s s a t t e n t i o n t o e r o s i o n i s r e q u i r e d because ranges are p r o t e c t e d from h i g h \ e l o c i t y winds by topography and because r a i n f a l l i n t e n s i t y i s low, e r o s i o n cannot be t o t a l l y i g n o r e d . (9) Rangelands, i n c l u d i n g those of B r i t i s h Columbia, are the home of w i l d l i f e as w e l l as domestic l i v e s t o c k . Because p a r t of the p o p u l a t i o n i s i n t e r e s t e d i n w i l d l i f e from an economic, moral, or r e c r e a t i o n a l v i e w p o i n t , the c l a i m s of w i l d -l i f e t o ranges used f o r domestic l i v e s t o c k p r o d u c t i o n must be c o n s i d e r e d . F o r e s i g h t and p l a n n i n g s o l v e s t h i s problem t o mutual advantage. (10) O v e r g r a z i n g r e s u l t s i n i n c r e a s e d numbers of s m a l l mammals and i n s e c t s , many of which cause c o n s i d e r a b l e damage. (11) The broad concepts p r e s e n t e d i n t h i s T h e s i s a re i n t e n d e d t o i n t e g r a t e o v e r g r a z i n g and i t s e f f e c t s i n such a manner t h a t t h i s work may serve as a b a s i s f o r f u t u r e r e s e a r c h on the r a n g e l a n d s of B r i t i s h Columbia. APPENDIX A Doubt has been e x p r e s s e d r e g a r d i n g the l e g i t i m a c y of i n c l u d i n g d o m e s t i c a t e d g r a z i n g a n i m a l s among t h e components of an ecosystem or I ' b i o t i c community". P r o f e s s o r P h i l l i p s (154) makes a p o i n t of s e p a r a t i n g the e f f e c t of g r a z i n g h e r b i v o r o u s a n i m a l s n a t u r a l l y o c c u r r i n g i n the " b i o t i c com-munity", v i z . , the b i s o n and a n t e l o p e from the e f f e c t of g r a z i n g a n i m a l s i n t r o d u c e d by man. The b i s o n and a n t e l o p e are s a i d t o have c o - o p e r a t e d i n the p r o d u c t i o n of the s h o r t -g r a s s v e g e t a t i o n of the Great P l a i n s (129) and to have a s s i s t e d i n p r e v e n t i n g the i n v a s i o n of g r a s s l a n d s by the f o r e s t . D omesticated g r a z i n g a n i m a l s a re supposed to be d e s t r u c t i v e i n t h e i r e f f o r t s and t o p l a y no p a r t i n the suc-c e s s i o n a l or de v e l o p m e n t a l p r o c e s s (220). I t i s ob v i o u s t h a t modern c i v i l i z e d man u p s e t s the " n a t u r a l " ecosystems or " b i o -t i c community" t o a c o n s i d e r a b l e degree. However, i t would be e x c e p t i o n a l l y d i f f i c u l t i f n o t i m p o s s i b l e t o draw a n a t u r a l l i n e between the a c t i v i t i e s of the human t r i b e s , which presumably f i t t e d i n t o and formed p a r t of the s e " b i o t i c com-m u n i t i e s " and the d e s t r u c t i v e human a c t i v i t i e s of man and the modern w o r l d . The q u e s t i o n then becomes* " I s man p a r t of ' n a t u r e 1 , or n o t ? " Man i s regarde d as an e x c e p t i o n a l l y power-f u l b i o t i c f a c t o r which i n c r e a s i n g l y u p s e t s the e q u i l i b r i u m of f o r m e r l y e x i s t i n g ecosystems, even to the e x t e n t o f d e s t r o y i n g some of them. At the same t i m e j " human a c t i v i t y o f t e n forms new ecosystems sometimes of e x c e e d i n g l y d i f f e r e n t n a t u r e . As an e c o l o g i c a l f a c t o r a c t i n g on v e g e t a t i o n , the e f f e c t o f g r a z i n g h e a v i l y ehough to p r e v e n t the development of the p r e v i o u s l y mentioned f o r e s t growth i s b a s i c a l l y the same e f f e c t r e g a r d l e s s of how and when i t o c c u r s . I f such i s the r e s u l t o f g r a z i n g , t h e g r a z i n g a n i m a l s a re a v e r y i m p o r t a n t f a c t o r i n the biome a c t u a l l y p r e s e n t r e g a r d l e s s of how th e y got t h e r e , whether t h e y m i g r a t e d t o t h a t p l a c e by them s e l v e s or whether they were i n t r o d u c e d by modern man. The s u b s t i t u t i o n of one type of v e g e t a t i o n f o r a n o t h e r , be i t a g r a s s l a n d or a f o r e s t v e g e t a t i o n , i n v o l v e s d e s t r u c t i o n t o some degree; but i t a l s o i n v o l v e s t h e g r a d u a l e s t a b l i s h m e n t of a new v e g e t a t i o n c u l m i n a t i n g i n a c l i m a x t h a t i s w e l l d e f i n e d under the i n f l u e n c e of the f a c t o r s p r e s e n t . N eedless to s a y , when man i n t r o d u c e s g r a z i n g a n i m a l s such as c a t t l e , sheep and h o r s e s , r e s t r i c t i n g them w i t h f e n c e s and p r o t e c t i n g them by d e s t r o y i n g p r e d a t o r s , he s e t s up an ecosystem whose e s s e n t i a l f e a t u r e i s the e q u i l i b r i u m between the g r a s s l a n d and the g r a z i n g a n i m a l s . I n such a way t h e " b i o t i c communi-t i e s " may be a l t e r e d from one deve l o p e d i n d e p e n d e n t l y o f man - b but the e s s e n t i a l f o r m a t i v e p r o c e s s e s of the v e g e t a t i o n are the same, however the f a c t o r s i n i t i a t i n g them are d i r e c t e d . I t i s t h e r e f o r e e s s e n t i a l t h a t we have a system of e c o l o g i c a l c o n c e p t s which w i l l a l l o w the i n c l u s i o n of a l l forms of b i o l o g i c a l e x p r e s s i o n and a c t i v i t y . We must not c o n f i n e o u r s e l v e s t o the s o - c a l l e d " n a t u r a l " e n t i t i e s and i g n o r e the p r o c e s s e s p r o v i d e d as t h e r e s u l t of t h e a c t i v i t i e s of man. APPENDIX E S c i e n t i f i c and Common Names of P l a n t s D i s c u s s e d SCIENTIFIC NAME COMMON NAME A. GRASSES Agropyron inerme (Rybd.) Agropyron S m i t h i i (Rybd. ) Agropyron s p i c a t u m ( P u r s h . ) Bromus t e c t o r u m (L.) C a l m a g r o s t i s l o n g i f o l i a (Hook.) C a l m a g r o s t i s rubescens ( B u c k l . ) Elymus condensatus ( P r e s l . ) F e s t u c a a r i z o n i c a (Vasey.) Fe s t u c a idahoens i s ( E l m e r . ) ( T o r r . ) F e s t u c a s c a b r e l l a  Hordeum .jubatum (L.) K p e l e r i a c r i s t a t a (L ) Muhlembergia montana ( N u t t . ) O r y z o p s i s humenoides (Roem.& Poa p r a t e n s i s ( L . ) Poa secunda ( P r e s l . ) S t i p a comata ( T r i n . ) S t i p a Columbiana (Macoun.) Awnless wheatgrass Bluestem wheatgrass Bluebunch wheatgrass Downy brome ( C h e a t g r a s s ) Sand g r a s s Pine g r a s s G i a n t w i l d rye A r i z o n e f e s c u e Bluebunch f e s c u e Rough f e s c u e W i l d b a r l e y June g r a s s Mountain muhley S c h u l t . ) I n d i a n r i c e g r a s s Kentucky b l u e g r a s s Sandberg's b l u e g r a s s Common spear g r a s s Columbia spear g r a s s B. FORBS. SHRUBS, and' TREES A b i e s spp. A r t e m i s i a f r i g i d a ( W i l l d . ) A r t e m i s i a gnaphalodes ( N u t t . ) A r t e m i s i a t r i d e n t a t a ( N u t t . ) A s t r a g a l u s s e r o t i n u s (A.Gray) B a l s a l m o r h i z a s a g i t t a t a ( N u t t . B r a s s i c a spp. C i c u t a o c c i d e n t a l i s (Greene) Crysothamnus nauseosus ( P a l l . ) D e l p h i n i u m b i c o l o u r ( N u t t . ) Elaeognus commutata (Bernh.) G u t i e r r i z i a s a r o t h r a e ( B r i t t . & L a c t u c a spp. Lappula oc c i d e n t a l i s (Greene) L a t h y r u s o r c h o l e u c u s (Hook*.) Lupinus a r c t i c u s (S.Wats.) Madia spp. Nor t a a l t i s s i m a ( L.) F i r s p e c i e s P a s t u r e sage P r a i r i e sage Sagebrush Timber m i l k v e t c h ) Balsam r o o t Mustard s p e c i e s Water hemlock' R a b b i t b r u s h Two-coloured l a r k s p u r Wolf w i l l o w ( S i l v e r b ' e r r y ) Rusby) Broom weed L e t t u c e s p e c i e s L i t t l e b l u e b u r Creamy p e a v i n e A r c t i c l u p i n e Madia s p e c i e s Tumble mustard P i c e a spp• P i n u s c o n t o r t a (Dougl.) P i n u s pondorosa (Dougl.) Prunus melanocarpa ( A . N e l s . ) Pseudotsuga t a x i f o l i a ( B r l t t . ) Rosa spp. S a l s o l a p e s t i f e r (A. N e l l s . ) - Sisymbrium spp. Tragopogon p r a t e n s i s ( L . ) Zygadenus venenosus (S.Wats.) Spruce s p e c i e s Lodgepole p i n e Western y e l l o w p i n e B l a c k - f r u i t e d choke c h e r r y Douglas f i r Rose s p e c i e s ( w i l d ) R u s s i a n t h i s t l e M ustard s p e c i e s Ghost's beard Death camus BIBLIOGRAPHY 1. A l b e r t s o n , F.W., P r a i r i e S t u d i e s i n W e s t - C e n t r a l Kansas. Trans. Kansas Acad. S c i . Zfcl, 77, 1938. 2. A l b e r t s o n , F.W., E f f e c t s of Drought. Dust, and I n t e n s i t y of G r a z i n g on Cover and Y i e l d of Shor t Grass P a s t u r e s , E c o l . Monog. 1/t, 1, 1944* 3. A l b e r t s o n , F.W. and Weaver, J.E., Nature and Degree of Recovery of G r a s s l a n d From t h e Great Drought of 1933-1940. E c o l . Monog. 14., 393, 1944. 4. A l l r e d , B.W., Grasshoppers and T h e i r E f f e c t on Sage-brush on the L i t t l e Powder R i v e r i n Wyoming and Mont-ana. E c o l . 22, 387, 1941. 5. 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